turbo 383 LT1/misfire

Hi all.

Not a very auspicious start. :)

But, welcome to CamaroZ28.com. Since there's no "tech" content here, let's move this over the "The F-Body Lounge".

Hi all, (sorry about the last post, I got anxious). I have a ’93 LT1 w/ 383. The engine has a 4 cylinder misfire on the passenger side bank. When the chip is unplugged from the ECM all 8 cylinders fire (in limp mode).We’ve upgraded to the MSD late model vented Opti spark, the scan shows no codes and we’ve checked wiring for a short to ground, along with that I’ve also replaced the ECM. I’ve checked for different ‘burns’ and broadcast codes, the problem doesn’t seem to be chip related. To clarify the miss a little, the car showed up with a Moates G1 adapter and the chip was installed backwards. Vehicle obviously ran very poorly so I figured flipping the chip would solve the problem. When I flipped the chip it created the 4 cylinder, (all 4 on passenger bank) miss. I then figured prom was at fault so I purchased a new prom broadcast code bdld (vin correct) and installed it without the moates adapter. This made no change, making me believe chip and ECM are not at fault. Vehicle hasn’t run correctly since the new 383 motor was built making me wonder if there is a late model crank trigger wheel, or a wiring interchange issue with the late model opti spark. What is odd about all this is although not a good thing to do, if I remove the chip engine runs on all 8 cylinders? How can this happen? Please help, Lots of time and money spent already!!!!

Okay, time to move it back to a tech section then. :)

Fred, what do you think? LT1 or PCM diagnostics and programming or Advanced Tech?