Joejr88

I have a 95 Trans Am and I blew the motor, so I bought a motor out of a 94 Camaro and have it all installed but can't get it to run, it turns over, backfires and fire comes out of headers, my main question is there anything I have to change in order to run the the 95s ECU on a 94 motor? I know the opti Sparks are different but heard I can still use it with the 95s coil and pig tail.. really lost, the 94 had a m6 tranny but is now bolted to my 4l60 from the 95 if that makes any difference

Joejr88

Any help would be greatly appreciated

96Formula6spd

iTrader: (7)

Wiring 94-95 was the same. Sounds like you might has some wires crossed on the optispark. Can use a 94 opti spark as it was just the plug that changed. Transmission will not matter as the wiring harness,transmission and ecu are still set as an automatic. But sounds like a crossed spark plug wire. I would start there.

Joejr88

Ill take another look I guess.. retraced them 3 times but am going to compression test it tommorow so I'll make sure there all in order again

SS RRR

iTrader: (2)

Most likely some sort of timing issue. Check to see if fuel injectors are in their right ports as well.

Joejr88

I was thinking k it was a timing issue as well from the fiffrendi Opti I'll see if injectiors are firing and check over plug order and compression tonight and just start narrowing it down possible issues and let you guys know what happens thanks

Gojira94

iTrader: (4)

Agreed, no start issue is with ignition somewhere. True, the opti pigtail between spline drive on the 93-94 and 95-97 is different (pass. side of intake to opti), so you should be good, but those pigtails sometimes can be the issue with the opti side connection if it's a used part. Not telling you to go get a new one but examine the pins, clean them, test for continuity across all pins. Also, there is one important difference between 94 & 95 engine harnesses. Blue PCM connector pin D6 has a wire to pin U on the round connector on the transmission side to control the PWM solenoid (added in 95, 94 didn't have it). As long as you used the 95 harness from your own car, you're fine.

Joejr88

The pigtail is in good shape however forgot to say when I connect the starter I did I back wards (put the pcm on the ground) do u think I could of fired somthsome?? And have to get a new pcm or have it reflashed/programed? Otherwise could it just be a bad Opti spark? Never heard the motor run with it or have proof that's it's still good I was thinking about getting a new one and just returning it if thats not the issue. Has good compression spark and injectiors are firing at a stand still and need it out of the garage soon

Gojira94

iTrader: (4)

You follow the procedures here yet?

http://shbox.com/1/4th_gen_tech2.html#opti_test