System Description

SDS EM-2D is a microprocessor based, digital, programmable EFI system intended to control port type injectors. EM-2 allows you to access all points in the engine operating map with the engine running and alter them according to your own specific needs utilizing a hand-held LCD programming box. As such, the system can be used on virtually any engine type or displacement.

Please read the entire manual before attempting any hookup or running of the system. If you are installing an E or F system, you will need to refer to the supplemental manuals for those systems.

Theory of Operation

Air temperature, water temperature, manifold pressure, throttle position and rpm are all measured and taken into account by the ECU which determines how often and how long the injectors remain open. The ECU generates a precise triggering pulse which is fed to the injector driver to open the injectors. The manifold pressure or throttle position value multiplied by the rpm value determines the primary pulse width.

Fuel System

In order for any EFI system to function properly, an adequate supply of fuel at the proper pressure must be present at the injectors. This cannot be overstressed. Problems are invariably blamed on the electronics when in fact 99% of all running problems are due to mechanical deficiencies.

Vehicles with Factory EFI

If horsepower is similar to factory outputs, fuel tanks, pumps, lines and injectors should be adequate when installing EM-2. When increased power is desired on factory equipped engines, some or all of the fuel system components may have to be upgraded.

Vehicles without Factory EFI

We recommend that vehicles originally fitted with carburetors have a fuel system installed as shown in the following schematic:

Two fuel pumps are required. One from the main fuel tank to the surge tank may be of the low pressure variety but must be capable of keeping the surge tank full during full throttle operation. Fuel lines should be at least 8mm (5/16 in.) ID on engines up to 400 hp and 10mm (3/8 in.) On engines over 400 hp. The fuel injection pump must be adequate to supply full rated fuel flow at maximum design pressure for a given output.

As a rule of thumb, on gasoline, you will require about 5.7cc per minute per hp so a 300 hp engine would burn about 1710cc per minute. (300 X 5.7). On alcohol, double these figures. Injectors must also be capable of flowing adequate amounts. Total fuel flow divided by the number of injectors fitted will give you the minimum flow rate needed from each injector. We recommend running injectors to only 85% duty cycle. So, on a 4 cylinder engine with 300 hp, we would calculate 1710 divided by 4 = 428. 428 divided by .85 = 504. An injector flowing at least 500cc per minute should be used for this application.

If you already know the injector flow rate, you can calculate the maximum safe hp available with the following formula: injector flow rate in cc's per minute multiplied by the number of injectors divided by 7 equals maximum hp at 85% duty cycle. Using the above example, 500 X 4 divided by 7 = 286 hp.

New fuel lines may be run using rigid steel, copper or aluminum tubing. Flexible lines must be medium pressure hose intended for fuel injected applications. Working pressures can exceed 60 psi on turbocharged engines.

Fuel pressure regulators vary the fuel pressure according to manifold pressure. Fuel pressure at idle on most engines should be 2 to 2.7 Bar (30 to 40 psi on most engines. Wide open fuel pressure on naturally aspirated engines should be 2.3 to 3.0 Bar (35 to 45 psi). Fuel pressure on turbocharged engines should be around 2.5 Bar (35 psi) plus boost pressure.

Excess fuel not burned by the engine is returned through the regulator back through the surge tank, then back to the fuel tank. A fuel return line back to the tank is required.

The surge tank should always be mounted above the main EFI pump inlet so that fuel may gravity feed into this pump. Surge tanks ensure that the fuel supply will not be interrupted by air entering the system under high G situations. Fuel injected engines will not run properly with air in the system.

System Hookup and Mounting

Connect each component according to the schematic below. Most separate wires are marked and those with Weatherpack plugs are self-evident with regards to connection. Separate wire connections are as follows: Green to negative coil terminal or tachometer lead. Keep the green wire as far as possible from ignition wires. Red to battery positive or switched 12 volt source. If hooked to ignition switch, be sure that there is power in the circuit when the key is in the start position. Black wire on main harness to chassis ground. Short black wire on injector driver to chassis ground. Red wire(s) on injector harness to switched 12 volts positive. Grey wire to O2 sensor if used. Optional orange wire to fuel pump relay. Optional light blue wire to fast idle relay. Optional purple wire to RPM SWITCH relay. Note 4 cylinder injector harnesses have a single power wire while all others will have 2. For E and F systems, consult the appropriate manual supplement for additional wire hookups.

A 1 amp fuse should be placed in line with the ECU red power wire. Note if ECU power is

obtained directly from the battery, a switch should be placed in line to prevent the battery from being run down over time. Ensure that all connections to ground have proper metal to metal contact.

All wiring connections in the engine compartment should be supported in such a way as to prevent vibration from working directly on the wires, sensors and connector plugs. Tie wraps should be used for this purpose. Never run wires through jagged firewall holes unless a grommet is used. Keep all wires and especially the green tach wire on D systems and the Hall cables on E and F systems, as far from the ignition components and hot points as possible.

ECU /Driver Mounting

The ECU must be mounted in a moisture free location inside the vehicle. Use the mounting tabs to secure it to the chassis. The ECU should be mounted at least 3 feet away from the ignition coil and wires if possible, preferably behind a metal firewall.

The injector driver box should also be mounted inside the vehicle in a moisture free area on the injector side to minimize wiring problems. It is important to mount the driver so that it can properly dissipate the heat generated. Never wrap the driver in foam or place in a confined space without air circulation.

Temperature Sensor Mounting

The water and air temperature sensors both utilize 3/8 NP threads. The water temp sensor should be screwed into the cylinder head so that it can read water temperature during warmup INDEPENDENT of the water controller by the thermostat. Note air cooled engines are fitted with a cylinder head temp sensor for warmup enrichment. Thread size is metric 10 X 1.0mm. This is connected to the white wire on the main harness.

The air temp sensor should be placed in the intake manifold or induction pipes after any intercoolers which may be fitted.

Air and water temperature sensors may be fitted to your engine using either adapter bushings into the original sensor bosses or by drilling a hole into a suitably thick area in the intake manifold for the air temp or the cylinder head or thermostat housing in the case of water temp sensor.

If drilling into an area, be sure to check that the wires from the sensor will clear things like pulleys and exhaust pipes and that drilling will not damage anything underneath. The area should be a minimum of 5mm (.200 in.) thick and should be pilot drilled before final drilling with a 37/64 drill. Both sensors use 3/8 NP threads which are tapered threads. When tapping, be careful not to go too deep or the sensor will not tighten properly. The sensor should thread into the hole half to three quarters of the way in with mild pressure.

Be sure to clean out all chips from the drilling and tapping operations before installing the sensors. Two or three wraps of teflon tape should be used on the final assembly. Sensors should be tightened until snug with a short wrench. A wire tie should always be used to secure sensor cables to prevent vibration breakages.

Map Sensor Mounting

The MAP sensor if used should be mounted in a moisture free area close to the intake manifold and connected using a length of 3mm (1/8 in.) Vacuum hose to the intake manifold DOWNSTREAM of the throttle body. Always try to mount the MAP sensor with the vacuum port facing down. The placement of a .025 to .035 inch orifice in the vacuum hose may be required on some installations to reduce MAP fluctuations

Throttle Position Sensor

Systems not using a MAP sensor rely on the TPS for both acceleration enrichment and load sensing. The TPS is used on ALL systems to supply accelerator pump information to the ECU. EM-2 systems are not supplied with a TPS as standard. Your stock TPS may be used if it is of the potentiometer type. Most cars made after 1984 use a potentiometer type TPS.

Spare pins and a plug will be supplied with your system to allow grafting onto your stock TPS

wiring. You can cut your stock TPS wires a few inches behind the plug and crimp on the 3 pins to the 3 wires used. Snap the pins into the supplied plug as outlined in the next section.

If you have ordered the optional TPS kit, your wiring harness will already have the 3 pins crimped onto the TPS cable. There are 2 different TPS's. One is identified by a grey top and drive is for clockwise opening throttles. The other has a black top and is for counter clockwise opening throttles. Make certain that you have the proper TPS for your installation.

You can check this by holding your throttle body with the shaft end which you intend to mount the TPS on facing you, then open the throttle. If the shaft rotates clockwise, you need the grey TPS. IF it opens counterclockwise, you need the black version. The pins are plugged into the 2 TPS's differently: The TPS plug has the numbers 1,2 and 3 stamped into it on the top, back face. Grey TPS's are wired as follows: pin 1- red, pin 2- white, pin 3- black. Black TPS's - pin 1 - black, pin 2- white, pin 3- red. Pins are snapped into the back on the plug then the blue pin lock is slid back towards the pins so that it is flush with the black plug face. Be sure that the pins are in the correct hole before snapping in place as they are impossible to remove once inserted. Both TPS's feature identical 5/16 D type drives to fit most popular import throttle bodies. Mounting may be accomplished with an aluminum adapter plate bolted to your throttle body. Be sure that the plate is of the correct thickness to ensure that the throttle shaft will not bottom out and cause binding.

Using OEM Throttle Position Sensors

Many engines are already equipped with an SDS compatible TPS. Your system has included a 3 pin plug and 3 snap-in pins to plug into the main wiring harness plug labeled TPS. Not all TPS's are compatible with SDS, many are switches and not potentiometers. The SDS unit must use a potentiometer type TPS connected to the ECU for acceleration enrichment. The following procedure to determine correct wire hookups should only be attempted by people who know how to use an ohmeter and understand basic electronic theory.

Incorrect hookup of the TPS wires to the wiring harness can seriously damage the ECU and TPS. This damage is not covered under warranty.

The following applies to 3 pin TPS's:

Make sure that the TPS is mounted on the throttle body as it would be in normal operation. Set the ohmeter on the 100K ohm range. Place meter leads on TPS pins. Rotate throttle shaft and shuffle leads between the TPS pins until you see a constant resistance reading between two pins which does not change as the throttle is rotated. These 2 pins will be called the OUTER pins for now. The remaining pin will be called the CENTER pin. The center pin will be connected to the white or green wire ( pin 2) on the wiring harness plug marked TPS. Connect one meter lead to the CENTER pin and the other lead to one of the OUTER pins. Open the throttle slowly. If the resistance increases as the throttle is opened, this OUTER pin will connect to the black TPS wire. The other OUTER pin will connect to the red wire on the TPS plug.

If the resistance decreases as the throttle is opened, then this OUTER pin will connect to the red wire on the harness and the other OUTER will connect to the black wire on the harness.

On OEM TPS's with more than 3 pins, 3 of the pins may be for the potentiometer and the remainder may be switch contacts. SDS does not use the switch contacts.

By shuffling meter leads to different pins on the TPS and opening and closing the throttle while watching the meter, you can identify the pins that connect to any internal switches. The switch or switches will most often share one pin with the potentiometer. Open and close the throttle all the way while checking resistance. The resistance will change from zero to infinite or vice versa as the throttle is moved. Once the 3 potentiometer pins have been found, the other pins can be ignored.

To verify proper connections, power up the system and measure the voltage from the black to center (white) wire. The voltage should increase as the throttle is opened. I Gauge 2 mode, in the AP window you can verify proper TPS hookup by opening the throttle rapidly and watching the AP value. The value should go up to 10-30 for a half second or so then tumble back to zero within 1.5 seconds.

Ignition Wires, and Interference Problems

Always use radio suppression type spark plug wires. NEVER use solid core wires. We recommend Magnecor or NGK. Try to mount the ECU as far from the ignition system as possible. Ignition interference problems usually show up as gibberish or strange symbology in the programmer screen. It is also not a good idea to route any of the SDS wiring near the ignition system. This is especially important on Hall sensor cables (E and F system).

LCD Programmer

The programmer allows you to access all points within each parameter. When powered up, SDS EFI should appear in the LCD window. From here, parameters may be called up by pressing the right or left parameter select buttons (< or >). As each parameter is gone through, the next parameter will appear in the window. Parameters will appear in the following order from left to right: GAUGE, GAUGE 2, MAGNET SEEN/NOT SEEN (E,F units only), RPM SWITCH, SPARE 1-2, VALUES LOCK, CLOSE LOOP ON, OFF, CL LO RPM LIMIT, CL HI RPM LIMIT, CL MAP LO, CL MAP HI, KNOCK RETARD (E,F only), MAGNET POSITION (E,F only), AIR TEMP, START, RPM IGN (E,F only), IGN RET/MAN PRESS (E,F only), ENGINE TEMP, MANIFOLD PRESS or TP, RPM FUEL, ACC PUMP LO, ACC PUMP HI then, back to GAUGE.

The parameters will automatically loop back to the opposite end upon reaching one of the end selections. By holding down either the right or left parameter select buttons for more than 2 seconds, ranges will advance at the rate of 8 per second until the button is released at the desired location.

Within each parameter, there are a number of ranges with a corresponding value number beside it. This value number is the one that will be changed to alter the injector pulse width. IE. RPM FUEL 5250 57. RPM FUEL is the parameter, 5250 is the range and 57 is the value. The value number may be any number between 0 and 255. The larger the number, the more fuel will be injected at that parameter and range. By pressing any of the + or - buttons while a parameter is selected in the window will change the value. Don't play with these unless you want to change the value.

To change a value, use one of the 4 buttons labeled +1, +10, -1, -10. Each button will change the value in the window each time it is depressed by that amount. IE. With a 57 in the window, hitting the -10 button once will change the value to 47. The +10 and -10 buttons should only be used for quick, radical adjustments. Again, by holding down these buttons for more than 2 seconds, values may be changed quickly to the desired figure. For GAUGE MODE operation, see that heading. The VALUES LOCK feature must be selected off in order to program.

RPM (RPM FUEL)

The rpm band is divided into ranges, usually 250 rpm apart. These values should usually be fairly close to each other varying only with the torque curve of the engine. It is important to note that the number of injections are doubled when the rpm is doubled regardless of the values entered.

As a starting point, refer to figure 3 to get an approximate RPM FUEL value to enter for your engine. You will need your injector flow rate and engine displacement to use this chart. Injector flow rate is in cc's per minute. If your flow rate is in pounds per hour, multiply by 10 to convert to cc's per minute. For example a 30lb./hr. injector would convert to roughly 300cc/min. Take your engine displacement and divide by the number of cylinders to get your displacement per cylinder. Cross your injector flow rate with your displacement per cylinder to find your RPM FUEL value. Enter this value right from idle rpm to redline rpm as a starting point. This chart is applicable for gasoline. If you are using Methanol, double the fuel value in the box.

RPM values therefore only compensate for the volumetric efficiency or breathing differences related to rpm. RPM values SHOULD NOT rapidly increase with increasing rpm on most applications. See figure 4 for clarification.

Change the RPM value at whatever the engine rpm is at idle in Gauge 1 mode to obtain a smooth idle before adjusting any MAP values.

Lower RPM values should rarely be less than 40 unless the engine is fitted with extremely large injectors. The ECU multiplies MAP or TP value by the RPM value to arrive at the primary pulse width. With this in mind, if you enter a 0 or 1 in either the MAP or RPM charts, when the system crosses that point, it will shut off the fuel.

Each RPM FUEL value should be adjusted for best running at wide open throttle/low turbo boost. Use caution at high throttle openings with severe stumbles. You can melt the pistons if the mixture is too lean. Changing the values by 10's until a stumble disappears is the quickest way to get the setup close. Values can be fine tuned later on. RPM values should follow the torque curve of the engine. The highest value should appear at the torque peak rpm not the power peak. See figure 4.

Often people have their RPM FUEL values very incorrect and then find themselves having to reslope the entire 64 manifold pressure values, which can lead to further problems. When the RPM FUEL values are setup correctly the majority of manifold pressure values can be left unchanged, thus greatly simplifying tuning of the engine.

RPM values should follow the torque curve of the engine. The highest value should appear at the torque peak rpm not the power peak. See figure 4.

Manifold Pressure (MANIFOLD PRESS or MP)

Data in the manifold pressure chart determines the relationship between vacuum and boost and the amount of fuel injected. Standard EM-2 systems have a negative sign preceding all vacuum numbers in inches of mercury, all boost numbers are in psi and have no sign in front of them. All units are pre-programmed with a standard MAP value chart depending on the MAP sensor used. These values should be close, so most initial programming is usually done on the rpm values. MAP values should increase roughly proportionally as MAP increases.

If the engine appears to be too rich everywhere, lower the RPM FUEL values across the board. Do not start re-sloping the MAP values as this often leads to people getting way off track.

Since idle mixture is difficult to pre-program, the user will almost certainly have to adjust the values in this manifold pressure range. Most engines will idle between 10 and 20 inches of vacuum so this is where the idle adjustments will be made. Idle MAP values work best by having them in the range of 25-35. Initially, you should leave your idle MAP values as per the standard MAP chart and only adjust the RPM Fuel values to obtain a smooth idle.

Select gauge mode to get an idea of what manifold pressure your engine is idling at. Select the closest range to this MAP by using the parameter select buttons on the LCD programmer.

If the mixture knob is to the left of 12 o'clock at idle, the mixture is too rich so the value in the window will have to be reduced by hitting the -1 or -10 buttons until the knob can be advanced to the 12 o'clock position. Use caution at high throttle openings with severe stumbles. You can melt the pistons if the mixture is too lean. Always go richer first with the knob to see if the stumble gets worse. Return the knob to the 12 o'clock position before working on the next range.

MAP values should increase in a reasonably linear fashion. They should not go up by one or two per location then suddenly increase by 5 or 8 per location, except possibly at idle.

If you wish to shut the fuel off during deceleration, this can be accomplished by entering 1's at the low vacuum numbers as seen in the example map. You cannot do this on TP systems. There are 3 different MAP sensors used with the system which cover a different range of pressures. The slope of the values will be different with different sensors.

If the idle speed is fluctuating up and down, move to the manifold pressure ranges just above and below where the engine is idling at. Make slight adjustments here until the idle is smooth.

Idle MAP values often work best when the values are the same over the whole range of idle MAP ranges (2-3 ranges). If the MAP fluctuates over more than 3 ranges at idle and you cannot get a smooth idle, you may have to install a .025 to .035 inch orifice in the MAP sensor line.

Refer to figure 5 if you do not understand the MAP concept.

For setting cruise and higher power MAP values, the same procedure as above applies. Set the programmer to Gauge 1 mode and increase MAP with the throttle until you identify a rich or lean spot either with the mixture knob or mixture meter. For example let's assume that at -8.42 to -6.81 inches we have a slight stumble and the mixture meter reads very lean. We continue to hold the throttle steady within this range while watching gauge 1 mode. Now, we turn the mixture knob richer until the stumble is no longer evident. The knob is turned to around +12% to make the engine run smooth. Now, we can go into the manifold pressure values to the ranges spanning -8.42 to -6.81.We can bump these up from say 90 to around 100 to see if we have made them rich enough. Remember to turn the knob back to its 12 o'clock or 0% position to verify your change. This will have to be repeated at all MAP sites where the mixture is not right.

When programming, remember to change only one variable at a time. To hold MAP constant, use a high gear and the brake or a hill to keep rpm from changing as you open the throttle. Make the change then go back to gauge, reestablish the range that you were working on and check the mixture again.

When using the mixture meter, most engines have to idle quite rich to be smooth. Under light load cruising conditions, most engines can be run quite lean for good fuel economy. Under full throttle and boost conditions, the mixture needs to be quite rich to produce maximum power and suppress detonation. It is normal for the mixture meter to go full lean when the throttle is released while in gear if 1's are entered in the high vacuum areas of the MAP ranges.

Throttle Position (TP or Throttle pos)

This section applies only to systems not using a MAP sensor. The TPS must be adjusted properly to supply correct data to the ECU. To do this, first select gauge mode on the programmer. In the top, left corner TP will appear followed by a 2 digit number between 0 and 64. These numbers refer to throttle plate position. With the throttle closed, rotate the sensor until a number between 4 and 8 appears behind TP. The TPS should be tightened down at this point.

Each number or position will have a corresponding value number beside it between 0 and 255, This value number determines the amount of fuel injected at that throttle position. Once the engine is started, the value number corresponding to the closed throttle position should be increased if the mixture knob is to the left of 12 o'clock or decreased if the knob is to the right of 12 o'clock. The aim is for smooth running with the knob in the straight up position.

Values only have to be entered for the position numbers from closed to open throttle. TP values should increase rapidly in the first 10 -20 numbers then slowly flatten out towards full throttle. Idle TP values should be in the 25-35 range. TP values multiplied by the RPM values result in the primary pulse width so the more air being admitted by the throttle plates, the higher the corresponding TP value should be.

Acceleration Pump (ACC PUMP)

This function adds to the primary injector pulse width when the throttle is rapidly opened. There are 3 adjustments to make for the acceleration pump. Two adjustments are made with the programmer and the other one is done with the trimmer potentiometer in the ECU accessed through the ACC hole in the top cover.

The ACCPUMP LO RPM value controls action from 0 to 1875 rpm. The ACCPUMP HI RPM setting controls action above 1875 rpm. Both parameters must have a proper value entered for proper engine response.

To set this parameter properly, snap the throttle open quickly. If the engine hesitates, change the value. If the hesitation is worse, you have changed the value the wrong way. Repeat this procedure on both HI and LO settings until engine response is acceptable.

The trim pot in the ECU controls the sensitivity to slow throttle movements. This control is very important just out of the idle range. Set this control by opening the throttle slowly from the idle position. Adjust for the smoothest possible acceleration. The trim pot is normally between 11 and 2 o'clock. Do not turn the trim pot fully clockwise as this causes extreme sensitivity of the circuit to randomly dump fuel into the engine resulting in rough running. Acc pump values are generally between 10 and 50 on most applications.

If changing the values will not make the engine respond properly, check to make sure that the TPS is hooked up correctly. You can check for proper pump operation by first selecting GAUGE 2 mode. With an ACCPUMP LO RPM value of 10 entered, you should see the AP number increase from 0 to a higher number when the throttle is rapidly opened, then as the throttle movement stops, the number should quickly return to 0. The AP number should always be 0 when the throttle is not moving. If not, it indicates an intermittent connection or a damaged TPS.

Start (START)

Start enrichment is provided for under the START parameter. The ECU takes its cues from the water (or head temp) sensor and injects extra fuel for the first 256 injections after the ECU detects crank rotation. This function is activated every time that the engine is started no matter what the water temperature is. It is critical for proper starting, especially in cold climates.

The value entered at a particular START water temp determines how much will be added to the primary pulse width to aid starting. Injector flow rates will have a large effect on these values. Large injectors will require smaller values on the same engine compared to smaller injectors.

At colder temperatures, the values are high, tapering off as the engine warms up. At temps over 100 degrees F, most engines do not require much extra fuel so the values should be low here although on some engines hot starting may be improved with some extra fuel to aid flushing boiling fuel from the injectors. Experimentation is required for a satisfactory setup here.

Once the first 256 injections have occurred (3-7 seconds), the ECU reverts to Engine temperature for warmup enrichment. These two parameters should not be confused.. The START function is automatically reset after 2 seconds after the engine stops turning.

Engine Temperature (ENGINE TEMP, ET)

The value in this parameter determines the amount of extra fuel injected to compensate for a cold engine during warmup. Liquid cooled engines use a water temp sensor and air cooled engines use a cylinder head temp sensor to supply this info to the ECU. You should aim for a 0 value when the engine is at normal operating temperature. Most engines will not require extra fuel after 100-120 degrees F. Temperatures can be displayed in F or C. The values should decrease in a fairly linear fashion from cold to operating temperature then have 0's entered above this threshold.

Some engines like a little additional fuel when hot starting to flush the injectors. Under heat soak back conditions, this extra fuel will be added until water circulation brings the water temperature below this threshold. If you are doing this be sure to only enter numbers above the water temps which are in the normal operating range.

As a reference, a value of 127 would add 50% to the pulse width and a 255 entered will double the pulse width.

By flicking back between gauge mode and water temp you can make adjustments while the engine is warming up. Each time the ECU updates to a new ET in gauge mode, you can go to that ENGINE TEMP in the window. Now turn the knob richer and leaner and note where the engine starts to run rough on each side of 12 o'clock. If it runs rough say at 10 and 2 o'clock, you probably have the water temp values about right. If not, adjust the ENGINE TEMP value at the water temp displayed currently in gauge mode.

Temperature (AT or AIR TEMP)

The air temperature correction map is pre-programmed when delivered. It provides an absolute density correction relating to cues from the air temperature sensor. This parameter should only be adjusted when it can absolutely be determined that a change in induction temperature causes the engine to run rough. AT is displayed in GAUGE mode.

On some engines, there is considerable heating of the induction air in the intake manifold, especially on non-crossflow types. In these cases, it is important that the air temp sensor be located close to the intake ports. If the sensor is placed too far away, the engine will tend to run rich because the sensor is not reading the true temperature of the air entering the engine.

On turbocharged engines, the sensor should be located in a position where it will be wetted by high velocity air after the intercooler. The wide range of temperatures that these engines operate over dictate that the sensor detect changes as quickly as possible.

Heat soak-back after shut down or prolonged idling can cause starting and running problems. Fuel can boil in the injectors and fuel rails making it virtually impossible to meter fuel accurately. Don't blame these problems on the system. Changing the air temp sensor location may help this problem. Be aware that conduction from water or exhaust heated manifolds may give false air temperature readings.

Gauge Modes

Calling up the gauge modes allows you to see in real-time, the sensor inputs to the ECU. This is useful for diagnosing sensor problems as well as programming. In gauge 1 mode (obtained by pressing the gauge button once) the LCD screen displays RPM, manifold pressure, air temperature and engine temperature simultaneously. If you encounter a strange problem or stumble, always select the gauge modes first to see if everything makes logical sense. Most problems can be quickly diagnosed here if you understand the system. The gauge button allows quick access to the gauge mode and upon pressing the button again, return to the previous parameter and range.

Gauge 2 mode can be accessed by pressing the right scrolling button (>) once when in gauge 1 mode. Gauge 2 displays mixture knob position, acceleration pump action, injector duty cycle and ignition timing in degrees BTDC on E and F units only.

Closed Loop Feedback Control (CLOSE LP or CL)

EM-2 systems are equipped with closed loop mixture control capable of taking cues from an oxygen sensor. In closed loop mode, the ECU attempts to hold the air/fuel ratio around stoichiometric (14.7 to 1 AFR for gasoline). The O2 sensor sends a DC voltage to the ECU in proportion to the free oxygen present in the exhaust stream.

If the sensor detects a lean condition, the ECU increases the injector pulse width to compensate and vice versa. Since there is a delay time between sensing and correction, the air to fuel ratio will continuously fluctuate slightly to either side of stoichiometry. This condition can be seen when using a mixture meter for setup. Holding the mixture close to the stoichiometric range is essential for the lowest possible emissions when the engine is fitted with a catalytic converter. Closed loop operation is not possible with leaded fuels or on SDS systems using TP for load sensing.

Many engines will not tolerate being idled at the relatively lean mixtures associated with closed loop operation nor will they safely tolerate these lean mixtures at full throttle, therefore the closed loop mode has rpm and manifold pressure limits, outside of which the ECU will switch out of closed loop into open loop (programmed values) mode. The ECU will also switch out of closed loop when the throttle is opened quickly. Closed loop will not be engaged by the ECU until the engine temperature exceeds 35C (95F) and the sensor voltage first exceeds .625 volts. The rpm and MAP must also fall within the programmed limits.

The following limits are programmable: CL LO RPM LIMIT and HI which determine where the ECU will discontinue closed loop control at. If you select 1500 and 4500 RPM respectively in these slots, closed loop operation will be discontinued whenever the rpm goes above or below these limits. The same thing applies for the manifold pressure limits, CL MAP LO and CL MAP HI. The engine must operate within these 4 limits or the ECU will revert back to open loop. CLOSED LOOP OFF can be selected if you wish to disable the feature. The grey wire must be connected to an oxygen sensor and CLOSED LOOP ON must be selected to set the closed loop function.

The O2 sensor will not supply reliable information to the ECU when cold (below 600 degrees F). A 3 wire heated sensor will give better results over an unheated one. Software limits prevent the ECU from adding or subtracting more than 25% to the primary pulse width in closed loop so it is important that the open loop fuel values are reasonably close to correct for proper functioning of the closed loop control.

Closed loop operation in most OE applications is generally limited to cruising conditions. Never program in limits corresponding to high power, high rpm conditions. Severe engine damage due to lean mixtures can result. A lean stumble is often apparent when the engine is unhappy about running in closed loop. Limits should be set to avoid these conditions. A mixture meter is highly recommended for system setup.

As stated before, many engines will not idle smoothly in closed loop mode. We recommend as a rough guideline, setting the CL LO RPM LIMIT no lower than 1500 rpm and the CL HI RPM LIMIT no higher than 70% of the redline rpm limit. Likewise, closed loop manifold pressure limits should preclude the low vacuum idle conditions as well as the high throttle ones. Set the CL MAP LO limit 3 to5 inches above the normal idle MAP value and the HI limit around -5 inches for naturally aspirated engines and from -5 to 2 psi boost on turbo/super charged engines.

In CLOSED LOOP ON/OFF mode, ON/OFF is selected with the +1 and -1 buttons. In the other 4 CL modes, the +1,-1 buttons are used to select the HI/LO points which will be in the same graduations as your RPM and MAP ranges. Always leave the closed loop off if no O2 sensor is connected and always leave closed loop off until all normal programming is completed.

Mixture Knob (KNOB)

The mixture knob controls the overall mixture across all ranges. In effect, it adds or subtracts a percentage to the injector pulse width. From the straight up or 12 o'clock position, the mixture can be leaned roughly 50% by turning the knob fully counter clockwise or 50% richer by turning it fully clockwise.

The knob is very useful in determining a rich or lean condition. It is important to leave the knob in its final position once programming is complete. Precise return of the knob to an exact position can be noted in gauge 2 mode under KNOB. A +, 0 or -% indicates rich, neutral or lean position. The knob may be disconnected if desired. This will leave the setting at 0% so it is important to complete proper programming with the knob at 12 o'clock if the knob is to be disconnected.

Disconnecting the LCD Programmer

The programmer may be disconnected when desired. We recommend that you place the display in gauge 1 mode before unplugging the cord. It is also a good idea to shut off the engine while doing this.

When re-connecting, the cord should be plugged back in, then the red reset button may have to be pressed to reboot the programmer.

Setting Safety Limits

Overrev and overboost protection can be obtained by selecting the point of fuel cutoff on the LCD programmer. If you wanted to shift at 7000 rpm, calling up RPM FUEL 7250 and entering a 1 would not allow the engine to exceed 7125 rpm. Boost limits are entered in a similar fashion by calling up the appropriate MAP range for fuel cutoff and entering a value of 1. We recommend that you also enter a 1 in the next range up as sometimes the engine will run through the first cutoff in the lower gears.

Theft protection can be obtained by entering a 1 at the lowest RPM FUEL range and removing the programmer. To restart, you would have to re-enter the proper value at that point.

Startup Procedure

Make sure that fuel at the correct pressure is present at the injectors. Turn on ignition and computer power. Crank engine, rotate mixture knob while cranking. If engine does not fire, see troubleshooting section.

Once the engine is running, use the mixture knob to get a smooth idle. Let the engine warm up to normal operating temperature. Once warmed up, attempt to set the knob near the center position (12 o'clock). To do this will most likely require adjustments to the values in the RPM FUEL chart. If the knob is on the rich side of 12 o'clock, the RPM FUEL values are too low and vice versa.

Your ECU comes pre-programmed with data that will in most cases, allow the engine to run in some reasonable fashion. These values will be based on the engine displacement and injector flow rates which you have provided us with. These are educated guesses so you may have to do a certain amount of re-programming. If you are unsure of what values to enter, refer to figure 3.

Refer the example maps if you get lost. It will give you an idea of what a good set of values should look like on a properly mapped engine. A mixture meter hooked to an O2 sensor may help you in programming your engine.

Once the engine is idling properly, RPM should be the first parameter worked on. Please note that the sample engine maps are only samples. They show the TRENDS of a properly mapped engine. If you double the injector size, the RPM values will be halved roughly. Figure 3 gives you the best stating place for RPM FUEL values.

On E and F systems, you must set the MAGNET POSITION parameter as soon as the engine is idling smoothly before performing any other adjustments. Refer to your E or F supplement.

RPM, MAP, Fuel Flow, Duty Cycle Concerns

Having both MAP and RPM values over 200 probably indicates that your injectors are too small or perhaps that fuel delivery to the injectors are insufficient. You can check the duty cycle slot in gauge 2 mode. At full throttle, the duty cycle should not exceed 85%. When duty cycle exceeds 100%, the engine will start to run lean. The injectors are too small in this case.

Make certain that the fuel delivery is adequate at full throttle. The engine will not run properly if fuel flow is insufficient in any part of the system. A fuel pressure gauge is a good idea. Pumps should be hooked in parallel not series to avoid cavitation.

MAP Sensors and Vacuum Sources

The solid state MAP sensor requires a smooth vacuum/pressure signal to relay a proper signal to the ECU. High amplitude pressure pulsations as you would have when connecting the sensor to a single runner behind a throttle plate on an independent runner manifold would be unacceptable. The MAP sensor may function properly on an IR manifold only if all runners are tapped for a vacuum signal and run into a small common plenum as shown in (Figure 6) leading to the sensor. If this is not feasible, the TP method of load sensing should be considered.

In gauge mode, if the MAP reading fluctuates a lot at idle, the hose to the sensor may have to be orificed . A .025 to .035 inch MIG welder tip can be used.

Naturally aspirated engines with small intake plenums and over 300 degrees of camshaft duration may work better using TP rather than MAP. All turbocharged and supercharged engines must use the appropriate MAP sensor for load sensing. MAP sensors are available in 1 Bar Ab for naturally aspirated engines, 2 bar for blown engines up to 15 psi of boost and 3 Bar for engines running up to 30 psi of boost.

Reset Button

If the LCD programmer is momentarily unplugged, the reset button on the side of the ECU must be pressed after plugging the programmer back in for proper operation to occur. The engine should be shut off when pressing reset. If ECU power is off while plugging programmer back in, the reset button does not need to be pressed.

The reset button is used any time that you wish to reboot the program to its initial position. This is indicated by SDS EFI in the window. This will appear in the window whenever power has been interrupted to the ECU or the ECU has performed an automatic reset. Software tells the ECU to reset automatically if an anomaly occurs or in the case of a program crash.

Pressing the right or left select button will take you into a programming mode.

Shutting off Power and Memory

Switching off power the ECU causes no ill effect for the system or ECU memory. As soon as you change a value with the programmer, it is permanently changed and stored in memory even with power off. Power interruption will cause the program to return to SDS EFI just as if the reset button was pressed.

Injectors

There are basically 3 types of injectors with regards to the flow orifices. One is the pintle style of which most older Bosch and Nippondenso types are. These have a small tapered spike or pintle which is pulled back when the magnet windings are energized, thus letting the fuel spray out. These are very reliable and quite resistant to plugging. We recommend Bosch, Nippondenso and OEM injectors only.

The second type is the GM/Rochester/MSD ball type. These have slightly better atomization but are more affected by dirt and varnish. In our experience these do not have the long term reliability of the pintle style. We specifically do not recommend the use of MSD injectors 2011 or 2012. These injectors are electrically incompatible with our drivers.

The third type is the disc style. These are made by various companies including Bosch/Ford and Lucas. These are popular in late model applications but also are not as reliable in the long term as the pintle style.

The second important injector characteristic is the resistance or impedance of the magnet windings. Low resistance injectors are characterized as peak and hold types. They will have a winding resistance from 1.7 to 3 ohms. They are opened with a current spike of 2.5 to 4 amps then held opened with a current of .75 to 2 amps. Injectors with a 2 amp open and .5 amp hold current cannot be used with our drivers.

High impedance injectors are referred to as a saturated type. Impedance is usually 10 to 16 ohms and they are opened with a sustained current of about 1 amp. Peak and hold injectors open more quickly at short pulse widths especially so the idle quality with large injectors fitted may be somewhat better.

Injectors come with various types of noses and fuel fitting ends. Early Bosch and Nippondenso injectors are available with an 8mm (5/16 in.) Hose barb fuel connection and a 16mm (5/8 in.) nose barrel. These are sealed with a flat type O-ring. These may use either an internal type electrical connection or the later type external style plug.

Later Bosch and Nippondenso injectors are identical to the ones above except that they use the late style electrical plug and an 11mm round O-ring to seal the fuel inlet connection.

The latest style which most modern and aftermarket injectors use, is the so called domestic O-ring style. These use 16mm (5/8 in.) round O-rings to seal both ends of the injector and use the late style electrical connection.

Toyotas built after about 1989, Subarus and some Nissan products use their own weird injectors, so beware. When upgrading OE installations with larger injectors, be sure to check that the O-ring and electrical connections are compatible.

All Bosch injectors are built to very high standards and are very robust. In the injector world, you get what you pay for- cheap injectors are usually poorly made, are non-linear with pulse width, won't last or have poor spray patterns. Buy Bosch or Nippondenso and you can't go wrong.

Don't expect super large injectors to offer a stock type idle or fuel economy. The maximum size that we recommend for race and performance use is 1.5 times the displacement of 1 cylinder in cc's per minute. So if you have a 2 liter, 4 cylinder engine with 500cc per cylinder displacement, the maximum injector size which will idle half decently would be a 750cc/min. injector. If you need more than this, you should consider the staged injector option which uses 2 injectors per cylinder, one for idle and low speed operation and 2 for high speed operation.

Fuel Rails

The fuel rail provides a volume of fuel for the injectors and usually serves to hold down the injectors to the intake manifold. With barb style injectors, separate injector hold downs must be made but because of the flexibility of the hose, precise alignment to the rail is less important. With O-ring injectors, all injectors must be at the same depth and be perpendicular to the rail. Injector to rail spacing is also very critical with O-ring types.

Injector Drivers

SDS injector drivers are externally housed in their own aluminum enclosures. They are available in 4 or 6 transistor types. Transistors may be triggered in ones, pairs, threes or fours depending on application. SDS is a non-sequential system like L-Jetronic Bosch systems.

Duty Cycle

Duty cycle refers to the amount of time that the injector remains open in relation to how much time is available at that rpm before the next injection cycle begins. This is usually expressed in percent and can be verified in gauge 2 mode under DUTY.

On occasion, very large injectors will cause rough idle problems due to the fact that the minimum triggering time admits too much fuel. Smaller injectors and/or the staged injection option are remedies to this problem. In cold climate, larger injectors may aid cold starting.

On constant high power applications such as marine or aircraft use, it is advisable to fit higher flow injectors than what might normally be used on street driven vehicles. These will limit the maximum duty cycles and enable the injectors and drivers to run cooler. The maximum continuous duty cycle should never exceed 70%.

Testing Injector Drivers

Drivers can be tested by disconnecting the input plug from the driver and taking a jumper lead from the positive battery post and quickly touching it to the DRIVER SIDE of the plug pins. On most systems, 2 injectors should click when the jumper is touched to each pin. Make sure that there is power on the red injector harness wire when performing this test.

Staged Injection Option

Staged injection allows your engine to run on one injector per cylinder (or rotor in the case of Wankel engines) at low load and two injectors at high load. The point of switching is preset and is non-programmable by the user.

At a predetermined pulse width of 8 milliseconds for example, the primary injector pulse width would be halved to 4 milliseconds and the secondary injectors would also be brought on line at 4 milliseconds. As such, no special programming is required.

It is important to have injectors of the same flow rate in both locations so that there is no bump in the fuel curve. Throttle bodies and intake manifold must be arranged so that air is always flowing past all of the injectors all of the time.

Injector harnesses are marked for primary and secondary if this is important on a particular system. On 4 and 6 cylinder staged systems, there will be two driver boxes instead of one and on Wankels, all systems are staged and use a single driver box.

Optional Fuel Pump Relay

SDS units can be equipped with an optional output to control a relay to switch the fuel pump off when the engine is not turning over. This feature is designed to prevent the pump from emptying the tank in a serious accident. The pump relay is energized for 2.8 seconds when power is turned on to pressurize the fuel rail until the ECU detects crank rotation.

Relay wiring is as follows: pin 30 to chassis ground, pin 85 to switched 12 volts, pin 87 to the fuel pump negative terminal, pin 86 to orange wire on main harness marked FPR. The relay switches the ground to the pump so you don't run a ground wire directly to the pump.

Fast Idle Option

The fast idle option consists of a solenoid valve which connects to the intake manifold via 5/16 vacuum hose and a relay controlled by the ECU via the engine temperature sensor. When the engine temperature reaches the preset point around 100F, the relay closes the solenoid to allow normal idle speed. Below this temperature, the solenoid is open bypassing additional air around the throttle plate. The preset temperature is not user programmable.

Relay connections are as follows: pin 30 to +12 volts, pin 87 to solenoid terminal, pin 86 to light blue on harness. The solenoid mounting flange must be grounded.

Solenoid connections are as follows: Hose marked PUMP is connected to the intake manifold with 5/16 vacuum hose. The other port may be connected to the air filter assembly or left open.

If the fast idle rpm is higher than desired, a restrictor can be placed in the other port hose to cut down the air volume bypassed. The MAP sensor automatically compensates for the extra air being admitted by the solenoid valve.

RPM Switch Option

The rpm switch control option allows the user to select the rpm where switch is activated. This option may be used to switch anything rpm dependant on and off especially variable valve timing and supplemental induction valves.

Wire connections on relay are as follows: pin 85 to +12 volts, pin 86 to purple on main harness, pin 30 and pin 87 are the switch contacts and need to be connected in series with the device being controlled.

To program rpm operation, go to the RPM SWITCH ON AT window in the programmer located to the right of the magnet window. The rpm that you wish to turn the switch on at is selected with one of the four + or - buttons. Below the rpm that you have selected, the switch is in the normal or low speed mode (off), when the rpm reaches the selected value, the relay is activated (on).

Values Lock

This feature allows you to lock out the programmer function to prevent inadvertent changes to your values. To lock your values, select VALUES LOCK window in the LCD programmer. The +1 and -1 buttons are used to select it to the ON or OFF position. You cannot program the system with VALUES LOCK ON selected.

Diagnosing Sensor Problems

The two gauge modes permit monitoring of the primary sensor inputs to the ECU in real-time. Rpm should be stable, agreeing with the factory tach. Spurious rpm readings usually indicate ignition or triggering interference.

Manifold pressure should increase as the throttle is opened at a given rpm. On TP systems, opening the throttle should increase the TP number. The TP number should not change if the throttle is not moving.

Engine and air temps should roughly agree with the ambient temperature if the engine has been shut down overnight. Very low temp readings on a warm engine indicate a defective sensor or a broken connection.

Switching to gauge 2 mode allows you to monitor the mixture knob position. It should read 0 at the straight up position. You should be able to get the reading to change from -49% to +49% by turning fully to both stops.

Acceleration pump operation is verified by snapping the throttle open. The AP number should rapidly increase until movement is stopped then the number should rapidly decrease to 0 again. The AP number should always be 0 unless the throttle is being moved. Rough running and a fluctuating TP or AP reading without throttle movement indicates a TPS problem usually.

Trouble Shooting

When encountering problems which can be identified to be linked with a specific area or function, always go to that section in the manual first and re-read it.

Will not start

Cuts Out at High Power

Not Running on all Cylinders

Cuts out Under Lateral G

1. Fuel pickup problem in tank.

SDS EFI in Window

Strange Symbology or black bars across the top of the LCD window

Poor Running, will not Respond

Will not rev up or has Miss

Erratic idling or running may be due to a poor or incompatible rpm signal to the ECU from the coil or tachometer lead. By calling up gauge mode you may look for this condition under the RPM parameter. It will show up as an unsteady reading when the rpm is steady. For example, if you see the rpm changing from 2000 to 4000 rpm in the window but the actual engine rpm is not changing, you have this problem. When this happens, extra fuel is dumped in and the engine will run very roughly as it is too rich.

Switching the green tach wire to a different source such as the tach pickup or negative side of the coil may solve this problem.

Warranty and Returns

EM-2 is sold for off road use only. New car warranties and emission standards are voided by installation of this system. Since SDS cannot control the installation or use of its products, we accept no responsibility for damage, loss or personal injury while using our products. By using SDS products the user understands and accepts this.

All SDS electronic components are guaranteed to be free from defects in workmanship and material for a period of 1 year from the date of sale to original purchaser if installed according to this manual. SDS shall make the sole determination with regards to all warranty claims.

Components are not covered if they have been altered in any way, physically damaged, subjected to moisture or incorrectly connected.

Defective components will be repaired or replaced as soon as possible at the discretion of SDS. Prior authorization from SDS is required before any warranty or returned item is accepted. All returns shall be shipped ONLY by air mail or UPS AIR. No returns are accepted after 30 days and all returned goods are subject to a 15% restocking fee as well as a charge for any

damaged components, cut wires or missing items.

Items shipped to us for warranty checks or testing which are working properly will be subject to a $40US charge plus shipping.

All SDS software and PCB design is the exclusive property of Simple Digital Systems. Unauthorized use or reproduction is a violation of copyright.

For Magnecor wires contact:

Magnecor

2550 Oakley Park Road 200

Walled Lake, Michigan 48390

USA

Phone 248-669-6688

For technical assistance contact your dealer or:

Racetech Inc.

G 1007, 55 Ave. NE

Calgary, Alberta, Canada

T2E 6W1

Phone 403-274-0154

Fax 403-274-0556

EM-2 F6 Supplement Version 3.0 Oct. 1998

System Description

The F6 system is an integrated fuel injection and direct fire ignition system designed for 6 cylinder engines. Engine spark timing is fully programmable for both RPM and/or manifold pressure/throttle position. Programming is done with the standard SDS hand-held programmer.

Triggering is accomplished with magnets attached to the crankshaft pulley and a Hall effect sensor fitted to the timing cover. As such, timing variations relating to belt and chain deflection or gear harmonics are eliminated.

Three, twin discharge GM coils are used.

Applications

The 6F system will work only on even-fire 6 cylinder, 4 stroke engines.

Theory of Operation

Three triggering magnets positioned 120 degrees apart are employed plus 1 synch magnet on a different radius. A double Hall sensor element detects the passage of each magnet and sends the pulses to the ECU. The ECU determines the exact rpm and manifold pressure, sums the programmed Spark retard values and calculates the appropriate delay for the specific conditions at that instant, then triggers the coils to fire at the precise time. The 6F system employs a waste spark strategy where the plugs on two cylinders are fired simultaneously, 1 on compression and 1 on exhaust.

By setting an initial offset value, MAGNET POSITION, the LCD programmer will display the actual ignition timing in degrees BTDC in real time in gauge 2 mode. Programming can then be accomplished in the simplest possible terms to understand.

Mounting the Hall Sensor

The Hall sensor assembly should be positioned so that the sensor element clears the crankshaft pulley face by 2 to 4 mm (.080 - .160). The sensor may be mounted to face either the front or the rear of the pulley depending on where the triggering magnets would be best located and clearance from other interfering items. It is essential to ensure that the Hall assembly bracket and wires will not touch the fan belt, pulleys or hot engine parts.

The square black sensor elements must be placed so that the magnets on the crank pulley spin over their centers with 1 to 2mm ( .040 to .080) clearance. Magnets will protrude about 1 to 1.5 mm past the pulley face. Note: on rubber damped harmonic balancers, the minimum Hall to magnet clearance should be 2.0mm to prevent contact due to pulley flex. Magnet contact with the Hall sensor will usually destroy the sensor. Always turn the crank by hand and check clearances before starting the engine.

Note that the longer of the two Hall elements (trigger) is 5mm (.200) further out than the other one (synch). The longer element will line up with the three trigger magnets spaced 120 degrees apart and the shorter one will line up with the single synch magnet on a 5mm larger radius on the pulley. Refer to figure 2.

Be certain to mount the sensor on the side of the pulley which is wide enough and thick enough to contain all 4 magnets. If this is not possible, a different pulley may have to be used or an aluminum disc can be machined and bolted to the pulley to house the magnets.

Usually, another bracket must be fabricated to attach to the timing cover bolts in order that the sensor bracket can be bolted in the proper position. Figure 3 shows a typical installation. The sensor bracket should be initially positioned in the center of its adjustment slot to allow maximum movement in or out for final placement once the magnets are in the pulley. The sensor is supplied with #10-24 Allen bolts. Slot spacing is 28mm (1.1 inches). Use a #25 drill and tap with a 10-24 tap. The sensor must be rigidly mounted on a bracket with no flex.

The wires leading from the sensor should be securely wire- tied every few inches to avoid vibration breakages. The ECU gets its RPM signal from the Hall sensor on the F unit instead of the coil as on the D model.

Mounting the Magnets

Triggering for the SDS ignition system is accomplished with high performance magnets mounted in the crankshaft pulley. These magnets must be precisely positioned both in relation to TDC and each other for proper functioning of the system.

The 6F system uses 3 magnets spaced 120 degrees apart on the smaller radius for triggering and 1 synch magnet spaced 40 degrees before the A trigger magnet on a 5mm larger radius. See figs 2 and 3.

Magnets measure 5mm long and 3mm in diameter. They are mounted in the crank pulley by drilling holes with a .125(1/8)inch diameter drill bit. This should be done in a drill press, very carefully, until the correct depth is reached. Hole depth should be 3.5 to 4mm (.140 to .160 inch) to allow the magnet to protrude 1 to 1.5mm (.040 to .060 inch) above the pulley face. The magnets can be mounted on the front or the back face of the pulley depending on which side is more suitable for magnet and Hall sensor placement. It is important to ensure that there is sufficient material thickness to drill a 4mm deep hole without breaking through and sufficient face width to allow mounting both sets of magnets.

The magnets and drilled holes must be free of oil and chips before gluing the magnets in position with 5 minute epoxy. MAGNETS MUST BE GLUED IN WITH THE WHITE END FACING OUT. A slight meniscus of epoxy is desirable around the magnet for best retention, These magnets are usually impossible to remove without destruction of the pulley and magnets so make sure you do this step correctly.

Two circles must be scribed on the pulley face using a lathe, calipers or divider. These circles must be 5mm (.200) apart and must allow the center of the Hall sensor elements to intersect these lines. Magnets will be placed along these circles. Draw an arrow with a marker on the magnet side of the pulley to indicate the direction of pulley rotation. This is very important to avoid confusion later.

Magnets should be positioned as per the following description and figures 2 and 3. In all cases, the crankshaft should be turned until the TDC or 0 mark on the pulley aligns with the pointer, TDC or 0 mark on the timing cover. With the Hall sensor loosely bolted in position, a mark should be made on the pulley where the center of the inner Hall sensor element intersects the pulley- From this mark, the first magnet (MAGNET "A") should be placed 80 degrees ADVANCED in the direction of crankshaft rotation. This is best determined using the paper gauge supplied with your system or a protractor. A line should be marked on the pulley at this position. Now, a centerpunch should be used to mark where the magnet will be placed along this line making sure that the pulley is thick enough at this location and that centerpunch mark lines up with the inner circle to coincide with the trigger element.

Next, the diameter of this scribed line must be precisely measured using calipers. The diameter of the scribed circle multiplied by 3.14, divided by 3.611 will give the dimension of 3 equidistant points along the scribed circle when using calipers or dividers. The first trigger magnet is labeled A, 2^nd is B and 3^rd is C, coinciding with coils A, B and C.

See figure 6 for clarification.

The single synch magnet will be placed along the outer scribed circle. This synch magnet will be mounted about 40 degrees ADVANCED in the direction of rotation ahead of the first A trigger magnet. Use the 40 degree paper template supplied or a protractor to locate this magnet and centerpunch for drilling. If you are unsure of mounting the magnets accurately and properly, have the work performed by a qualified machinist.

Aligning the Hall Sensor

Exact alignment of the Hall sensor elements with the magnets is critical for proper operation of the system. Proper alignment can be confirmed by calling up the magnet alignment mode in the programmer window.

F systems have a window to the right of gauge mode- The window is available by pressing the > button while in gauge 2 mode- The LCD Screen will read TRIG MAG SEEN or MAG NOT SEEN and SYNCH MAG SEEN or NOT SEEN. As a magnet passes the Hall sensor, the graphic will change from NOT SEEN to SEEN.

Reposition the sensor slightly until the SEEN graphic is displayed with the magnet lined up. Tighten the sensor bolts. Recheck by turning the crankshaft by hand, As each magnet passes the sensor, the display should change to SEEN momentarily. This window is only valid when the crank is turned by hand because the sampling rate of the programmer is too low to display this parameter with the engine running.

Make sure that there is at least 1mm clearance between the magnets and the Hall sensor (2.0mm on rubber damped pulleys) before starting the engine. Never attempt to start the engine until this step has been performed.

Initial Setup - VERY IMPORTANT

This involves calling up the MAGNET POSITION parameter. This step should be performed as soon as the engine is fired up and idling. Ignition timing is meaningless without first setting the MAGNET POSITION parameter properly. Note that MAGNET POSITION and RPM IGN are totally separate parameters.

A value of between 70 and 90 entered should allow the engine to be started. 80 would be a good starting point and is where the system is factory set.

STEP 1. Go to RPM IGNITION 500 and set that value to 10. Also set RPM IGNITION 750 and RPM IGNITION 1000 to a value of 10.

STEP 2. Make sure that all IGN RET/MANPRESS values below boost are 0.

STEP 3. Start the engine and keep it running below 1000 rpm.

STEP 4. Connect a timing light.

STEP 5. Change the MAGNET POSITION value until the timing light reads 10 degrees BTDC.

Once the MAGNET POSITION is set, it does not have to be changed again- it is only to tell the ECU what the "distance" between the MAGNET "A" position and TDC is. Once the above 5 steps are completed, you may enter your desired timing curve.

Ignition Programming

Ignition timing requirements differ widely between various types of engines so we can only offer general guidelines for ignition values. Optimal timing is best found on a dyno or by driving the car.

With this system, total timing is a result of the RPM IGNITION value minus the IGN RET/MANPRESS value.

To program ignition timing, two parameters RPM IGN and IGN RET/MAN PRESS are used. For example, if you want timing at 20 degrees BTDC at 2500 RPM got to RPM IGNITION 2500 and enter 20. For obtaining ignition retard under boost conditions, by entering a value under IGN RET/MANPRESS the system will retard timing by the amount entered at that boost pressure.(See figure 5)

For most engines running adequate octane fuel, a simple timing curve using only RPM offsets often gives excellent results. For high compression, naturally aspirated engines and turbocharged street engines running relatively low octane fuels and where fuel economy is important, a more complex curve taking MAP into account may be required. Timing may have to be retarded at higher manifold pressures to avoid detonation.

Systems not using a MAP sensor will use IGN RET/THROTTLE instead of IGN RET/MAN PRESS. Here, the throttle position sensor provides load information to the ECU. RPM values can be changed every 250 and 64 MAP or TP values are available for you to tailor your ignition curve.

If you have no idea what your ignition curve should look like, programming should be done by somebody who does, SERIOUS ENGINE DAMAGE CAN OCCUR with improper values entered. Excessively retarded timing can cause high exhaust gas temperatures while advanced timing can lead to preignition and detonation.

You should write down what you want your total timing to be with RPM first of all. Most engines want total timing between 5 and 15 degrees BTDC at idle- As RPM is increased, total timing is usually slowly increased from 1500 RPM up to 2500 to 4000 RPM- where full advance is usually in - most engines like 30 to 40 degrees total timing here. Often this figure is maintained right up to the redline- Figure 4 gives a typical RPM only timing curve along the lines above. This will work fine on most engines if you are unsure of what values to enter.

For RPM only ignition mapping, enter 0's in all the IGN RET/ MANPRESS or IGN RET/THROTTLE parameter slots.

For Street turbo engines, the IGN RET/MANPRESS parameter slots will have to be used to obtain optimum power and fuel economy running on pump gas.

Some engines may need more ignition advance when cruising to obtain maximum fuel economy. Since this system only provides for retarding timing with regards to manifold pressure, a different strategy is needed to effectively get "vacuum advance". The easiest way to achieve this type of MAP influenced timing curve is to enter a base value in IGN RET/MANPRESS of say 5 at all the ranges you don't want to retard or advance the timing. This will be the base retard value now instead of 0. At the MAP points that you wish to have total timing "advance", you can enter numbers less than 5. You will have to compensate for this strategy by increasing the values in the RPM IGN ranges by 5 so the total timing will be correct. At higher MAP values you can enter progressively larger numbers to pull back total timing under boost or high load if you wish. If you don't need "advance" under light load cruising conditions, IGN RET/MANPRESS values Can be kept at 0 until you want to pull back timing under boost, This is much easier to understand as well.

It is important to remember that total timing is the result of the RPM IGN value minus the IGN RET/MANPRESS value at that given instant of engine operation.

Figure 5 shows an example ignition map assuming 35 degrees total timing is optimal for best power but the octane rating is too low to tolerate this timing under boost. Timing must be retarded under boost.

There are hundreds of possible timing curves available with SDS to suit any engine, the previous examples are only hypothetical as mentioned before, efficient timing curves are best developed on the dyno.

Mounting the Knock Sensor

We supply a GM sensor for our applications. While other sensors may work with SDS, our system was designed around the GM unit. We can sometimes change a resistor in the ECU to suit other knock sensors.

The sensor is usually mounted in the block, within 2 inches of the top, close to the cylinders. It should never be mounted close any obvious noise generating components such as a fuel pump or camshaft lifters. In most cases, mounting it in the head is also a poor choice because of valvetrain noise.

A thick area of the block with a boss is the best place to drill a (13mm) .500 inch hole. The hole should be (13 to 16rnm).500 to .625 inches deep. Make absolutely sure that it is safe to drill a hole of this dimension where you plan to!

The hole should be tapped with a 9/16 UNF starter tap. Depending on the tap, you should only go in 4 turns to begin with, clean out the chips and try the sensor for fit. Keep tapping one turn at a time until the sensor threads in 4 to 5 turns with hand pressure. Stop tapping when the sensor will screw into the hole 6 to 7 threads with a wrench. Note that the thread on the knock sensor is a tapered thread.

An alternative to drilling into the block is to machine and thread a steel adapter to accommodate the sensor on one end and a stub with the thread to match those in an existing pre-tapped boss in your block, as noted in the previous sections, it may be necessary to change the sensor location if it is impossible to isolate engine noise while still allowing the ECU to identify knocking.

Knock Sensing Programming

The knock sensing option allows you to adjust the sensitivity and selectivity of the ECU to hear knock from the sensor and adjust the amount of ignition retard per knock.

Sensitivity is adjusted with the trim pot screw accessed through the hole in the ECU marked KN , The amount of spark retard is adjusted using the LCD programmer by calling up KNOCK RETARD and changing the reference value, A value of 3 will retard the timing 3 degrees for every knock that the ECU hears. Timing returns to the previous value at a predetermined rate if no more knocks are heard. This rate of return increases with increasing rpm.

It is important to adjust the sensitivity screw to ensure that the ECU is hearing only knock and not mechanical engine noise. Many engines go through various harmonics and the sensor is so sensitive that it can pick up noises which are not detonation and falsely trigger the sensing circuitry. This may severely retard the timing when in fact no detonation is present. The sensitivity adjustment allows you to tune out low amplitude noise, allowing only true knock pulses through to the ECU.

This condition is best diagnosed and remedied by first entering a 5 in KNOCK RET and 0's in all the IGN RET/MANPRESS slots. Set the pot screw in the middle of its adjustment range. Go to gauge 2 mode. Look at the IGN parameter- Now rev the engine up to redline in neutral with reasonably small throttle movements if possible. The ignition timing in the window should follow exactly what you have programmed in the RPM IGN slots. If you see the timing suddenly retard as you are revving the engine, it means that the knock sensor is picking up mechanical engine noise and the ECU is retarding the timing because it thinks it is knocking. Turn the pot screw COUNTERCLOCKWISE to filter out this noise.

You should be able to rev the engine up in neutral without the knock sensor retarding the timing unless the engine actually knocks. If this happens, there may be too much timing for the fuel octane that you are using. The sensitivity pot must be set so that the ECU only hears true knocking and no engine "noise". Remember, clockwise is more sensitive and counterclockwise is less sensitive. If you can't get satisfactory operation, you may have to try other knock sensor locations on your engine.

Since every engine is different, try experimenting with different KNOCK RET values. 1 to 5 would be the normal range. The maximum retard that the system can deliver is 20 degrees.

If you wish to negate the knock sensing option, you can enter a 0 in the KNOCK RETARD parameter. The knock sensing option can take the place of large amounts of MAP retard in some cases however, total reliance on the sensor while running unrealistically high amounts of spark timing may lead to running problems. We recommend using the knock sensor as a safety device rather than a primary timing control.

Proper location of the sensor and tuning of the sensitivity control along with a proper KNOCK RETARD value are essential for satisfactory operation of this option. Knock control is not a magic bullet. If the compression ratio or boost pressure is too high for the fuel octane you are using, either knock will occur or you will lose power by having to retard timing to prevent it. Constant hard knocking (detonation) will eventually destroy any engine, sometimes within seconds.

Ignition, Coil, Wire and Knock Hookups

The Hall sensor cable is plugged into the center 9 pin plug on the ECU, The yellow wire marked "KS" plugs into the knock sensor. The connections to the coil unit are as follows; Black wire to chassis ground- Red wire to positive switched 12 volts, Green to tachometer and 3 pin Weatherpack plug to 3 pin plug on main harness.

Coil placement can be in the stock location in most instances, The coil pack should never be bolted directly to the engine. As always, wires should be well supported and routed away from hot items. Always use radio suppression wires of the carbon core or spiral wound variety. Magnecor wires are highly recommended. NEVER USE SOLID CORE IGNITION LEADS WITH SDS. Note that the 6F system will usually require custom wires for fitment to the GM style coils.

Ignition wires must be connected properly. Ignition coils are labeled A, B and C . Because six cylinder engines have different firing orders and numbering systems, the following procedure should be used to determine proper spark plug wire hookup; referring to Figure 6, draw 3 intersecting lines about 120 degrees apart. Going in one direction around these lines, at the end of each line, write down the next number in your firing order sequence. As per the example in Figure 6, the wire connection to the coils will be: coil A- #1 and the plug 180 degrees across the chart from #1, Coil B- the second plug in your firing order and the plug straight across from it in your diagram, Coil C- the 3^rd plug in your firing order and the one straight across in your diagram. Figure 6 has an example for a Toyota straight six with a firing order of 1-5-3-6-2-4 so the coil/plug groupings are; Coil A-1 and 6, Coil B- 5 and 2, Coil C- 3 and 4.

Never turn over the engine or operate the ignition with the wires disconnected as this will often damage the coils. Coils damaged in this manner are NOT covered by warranty.

Ignition Wires

Solid core ignition wires must NEVER be used with SDS units. EMI/RF suppression wires should always be fitted. We recommend Magnecor or NGK wires for best results.

Troubleshooting

Will not start

1. Check power, ground. Test coils.
2. Check Hall sensor alignment.
3. Check MAGNET POSITION parameter and RPM IGN

Miss at high rpm

1. Check Hall sensor alignment.
2. Check Hall sensor air gap.

Testing The F Coils

If there is a need to check the coil box for proper operation the following procedure can be

performed. Disconnect the spark plug wires from the 3 coil packs. Now, wrap a 2 inch piece of solder or uninsulated wire around one output terminal on each coil. Position the ends roughly 1/4 inch from its adjacent terminal on the same coil.

Other wire connections are as follows: Red to +12 volts, Black to ground, Green to tach. Unplug the 3 pin Weatherpack connector from the coil pack. Connect a jumper wire to the positive battery post, then momentarily touch the other end to the red wire terminal (pin 1) on the COIL SIDE 3 pin coil connector. A spark should jump between the coil terminals on the A coil. Now, touch the jumper to the white terminal (pin 2) on the 3 pin coil connector momentarily. A spark should jump between the coil terminals on the B coil. Now, touch the jumper to the black terminal (pin 3) on the 3 pin coil connector momentarily. A spark should jump between the coil terminals on the C coil.