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Piggyback EMS Stinger with Ford EEC-IV - ED Falcon Project

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Hi everyone,

I have an ED Falcon that runs the factory EEC-IV computer. It has an electronically controlled 4spd auto trans, AC and ABS all controlled by the computer. I have an EMS Stinger 4424 v4 ECU here with a brand new loom. Have powered it up on my laptop and all working fine. This will be my first attempt at a injection/ignition ECU project. My goal is to use the factory ECU to run everything on the car including the auto and dash cluster, however use the Stinger to output injection, ignition, fuel pump whilst taking input from water temp, TPS and trigger related sensors. Note that this car is injected (6 individual injectors) with distributor. Luckily the Stinger has a base map for this car so should help the initial set-up to get it going. Ill start off with these questions as I'm bound to come up with more throughout this week. For reference, here are the pinouts for my ECU and also the wiring diagram for the Stinger:



1. Power and Ground: Can i just splice into this at the original ECU connector to power and ground both ECU's simultaneously?

2. TPS: Ford Pin 47 (0.7V closed 4.5V WOT) to Stinger Pin 6 (Signal for TPS)? Can this be spliced or better to remove from Ford EEC and dedicate to Stinger without causing any issues to EEC?

3. TPS: Ford Pin 26 (Sensor Reference Voltage +5v output) to Stinger Pin 22 (+5v)? Same as above regarding splicing or removing?

4. 02 Sensor: Ive got an Innovate MTLX on its way so just going configure and use this wiring/output to Stinger, leave narrowband connected to EEC, any issues this way?

5. Fuel Injectors: Will be running Siemend Deka 80lb bolt ins with 12ohms resistance. Ford Pin 58 is for cyl 1,3,5 (description: PWM on Fuel Injection). Ford Pin 59 is for cyl 2,4,6 (description: 0V off, 12V on). Can I just output Pin 58 to Stinger pin 23 and Ford Pin 59 to Stinger pin 11 - in effect using one injector output to hit all three injectors like factory? Will i run into any issues with overloading this output?

6. Distributor: Ford Pin 56 (PIP 0V-12V Ignition PIP) to Stinger Pin 8 (Trigger)? Just remove from factory wiring and connect to the end of shielded cable on Stinger loom? BTW don't think there is any Sync reference on this motor.

7. Ignitor: This has a single coil - little confused how I would trigger the spark in this application?

8. Fuel Pump: Should I just let the factory ECU do the fuel pump or will it run into issues because it won't be picking up a running engine therefore will just shut off pump?

9. Water Temp: Better off just running an additional sensor here to keep factory water temp working?

Will stop there for now, much appreciated!

Cheers, Michael

Hey Mick, this should be an interesting project. You're on the right track with keeping the factory ECU but piggy backing a stock ECU does need to be done carefully to ensure the stock ECU remains happy. I've answered your questions below:

1. Yes, no problem.

2. I'd splice the TPS signal to the stronger and retain it also going to the Ford ECU as it may be involved with the shift pattern.

3. You don't need the 5v from the stinger. You're better to just splice a sensor ground from the Stinger to the TPS sensor ground.

4. You shouldn't need the narrowband however if you remove the sensor you may end up with a CEL.

5. I'd run a separate loom for the injectors and wire them sequentially however this would require a sync input. Alternatively you can just wire up in batch fire but I'd suggest you refer to the Stinger manual on their requirements for doing this.

6. I'd assume so without having a look at the distributor wiring. There's going to be a ground too that will need to be connected. The factory ECU will also need the rpm input.

7. There will be an ignition output from the Stinger that connects to the ignitor module. You can think of the ignitor like a relay to control the current flow to the coil.

8. I'd use the Stinger but it's a coin toss.

9. There will be a gauge temp sensor that runs the gauge on your dash which will be a single wire sensor. The one for the ECU will be a 2 wire sensor. You can't share that with the factory ECU unless you can disable the pull up resistor in the Stinger. Worst case you can just add a dedicated sensor.

Hi Andre, thank you for taking the time out to reply in detail i appreciate it! Points taken on all of the above, will make it a lot easier to get this project firing.

1. Regarding the injectors, the Stinger manual states that the combined injector resistance for each output cannot be lower than 1.2 ohms. If I have 6x 12ohms Siemens injectors and had then all running off one output for batch fire, that would give 2ohms combined resistance for that output correct?

2. In fact, would that therefore mean I could combine the two pins on the EEC (58 and 59) and run them off a single output from the stinger? Worst case, can follow what you have already recommended and just run new wiring.

3. Regarding the distributor, I have attached a diagram from Microtech. I think you would normally run the ignition output to that distributor pin labelled 'Spout' to fire the coil, however I have read that if we do this then we don't have control over dwell and would therefore need to run an ignitor. Is there a generic one that you know can be used as the ignitor? (Thanks for the relay analogy makes a lot more sense now!)

4. You're right about the ground on the distributor - however it looks to already be grounded. Unless you mean ground the cable on the Stinger loom that's inside the shielded cable?

5. Distributor again, the ECU receives the RPM signal I'm guessing from that PIP wire that will be sending the signal to the Stinger. I believe the Stinger can disable the pull up resistor on the Trigger, would I be disabling this pull up resistor and splice/share the PIP signal to both the factory ECU and Stinger Signal wire?

Regarding Water Temp Sender, I don't believe the Stinger can disable this pull up resistor... Will more than likely run dedicated sensor

EDIT: mistake with pull up resistor

Thanks again!

Attached Files

Bump :)

Note with my above Q3, I think I'm going to go with a Haltech coil with inbuilt ignitor!



Hey all,

Have managed to almost finish this piggyback conversion. Have run a separate dedicated water temp sensor, installed a Haltech IGN 1A coil with inbuilt ignitor, the ECU is reading TPS, Water Temp, MAP and AFR (although completely off have to check the calibration, at least I have the correct one displaying on the innovate gauge itself for now). I have a very strange issue that I can't get to the bottom of around the trigger, here is the rundown. Keep in mind that we have wired everything on DTM plugs so I can easily go back and forth between having the Stinger piggybacked and having the OEM run the whole show as per normal:

1) If I send the PIP signal ONLY to the OEM ECU, the car will start and run fine on the factory computer (injectors connected to OEM)

2) If I send the PIP signal ONLY to the Stinger, there is no RPM signal and car will not start (regardless of the pullup resistor on or off, injectors connected to Stinger)

3) If I share the PIP signal to both the OEM and Stinger (regardless of the pullup resistor on or off), the car will not start or read RPM on stinger (injectors connected to OEM)

4) However, If I start the car with PIP just to OEM ECU, then while the car is running, i share in the PIP to the Stinger as well (I have it on DTM plug), then the motor momentarily stumbles, but goes back to normal operation running and the Stinger now sees a correct RPM signal!! (injectors connected to OEM). Therefore, in my mind, my wiring should be correct

We can't work out why this is happening. I have followed pretty much the same combination as people that have done this in the past with the only exception being that we are running a separate coil with in built ignitor. Most people would run factory coil with separate ignitor, or just connect straight to the TFI module in the dizzy with no ignitor.

Could it perhaps be due to the fact that i still have the factory ECU sending a spark output signal to the distributor module somehow screwing this up? Really stumped what's going on here so please shoot any ideas you may have for me to test!!




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