Ignition driver removal?

[altz1]

Hello,

I am new to the programmable efi world, so I ordered a vems with 8 igniton outputs to run my audi V8 in seq. fuel + ignition (COP), but as it turns out my COP-s (4wire) need 0-5v logic level drive instead on 12v grounding. So now I have to remove all the ignition drivers. Is this difficult, I mean what I other modification the ecu needs ?

thanks,

Allar

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Cut the IGBTs as close to the PCB as possible, then with a soldering Iron and solder sucker you will get a clean hole.  You then need to bridge the gate (middle pin) to the collector (lower pin going to the Econoseal plug)

[mattias]

If you're not in to modifying the ECU, you can do this externally as well. The power for the pull-up of the logic signal is the problem, you don't want it present when the ECU boots up or you'll send a signal to the coils and they will give off a spark when you turn the ignition on, which can cause a back-fire. I have  power to the pull-up taken from the fuel pump relay, as that is only active once the ECU is booted up and engine is running.

Of course, if you're not going to run with cam sync you can use the stepper motor outputs instead, there are 4 pins  for that on the EC18 connector.

In either case you must use resistors to limit the current, there is a thread around here somewhere but it's basically up to the type/model of coils you use.

[altz1]

Okey, I took a peek into the VEMS unit. Found the 8 IGBT-s. As I understand, the middle pin goes directly to the Econseal plug. So I have to cut those IGBT-s and basically bridge the middle pin (leg) and the left pind (leg) as the right is ground and I dont need it ? Are the IGBT-s driven by logic level signal which I will have to bybass from the IGBT-s now?

Sorry for maybe dumb questions, I am no electric guy by far. ;)

My active coils get theyr power woth master engine control relay. Allso the fuel pump and injectors get theyr +12 from there. It was set up like that from factory, it is some strong relay (60amps). The car is Audi S6 with 40v v8 engine.