Neilakamike

95 coupe,starts and runs on about 3 cylinders for about 30 seconds then smooths out and runs on all 8 like someone threw a switch. Traced fault to intermittent ground signal from PCM injector drivers. Bought rebuilt from Cardone,same problem,sent both to Cardones rebuilder,same result, will run on 96 pcm (obdII) but sets mil. any ideas?

Cliff Harris

It would appear that the fault is not in the PCM. You might have a problem with one of the injector fuses (INJ1 or INJ2) or a ground issue. Since each injector has its own injector driver it's unlikely that several of them act exactly the same at the same time.

See post #19 in this thread:

https://www.corvetteforum.com/forums...bank-fire.html

MrWillys

Ohm the injectors, it sound like bad resistance in the coils.

Neilakamike

The INJ1 an2 are both good with clean connections,I added a ground strap to the exhaust manifold bolt, I own an auto repair shop and have actually watched the missing ground signal from the pcm

MrWillys

If you have an injector that is going short to ground the injector driver overheats and shuts down until it cools. That's why I suggested checking the resistance value.

Neilakamike

All injectors ohm check within specs. when I put an OBDII computer in my car from a friends 96 the problems stop. I have sent 2 computers to SIA Electronics for rebuild and they do not work.I replaced the ground strap from the bell housing to the body with one to the exhaust bolt and have clean tight connections. Do I have a bad rebuild? what could I be missing?

Cliff Harris

Check the injector resistance when they are hot. Sometimes they go weird after they warm up.

Neilakamike

this is happening cold

Cliff Harris

You didn't mention error codes. Have you checked for any?

Neilakamike

dtc 18 injector circuit fault, i have been advised by more than one person that old injectors will overheat the drivers so i am trying a new set of injectors this weekend

Neilakamike

Tried new injectors without positive results. Anyone with ideas about computer input?