Well, the other day I was driving the car pretty hard, and it had been backfiring here and there.. odd thing about that is it would bog a bit, then backfire and pick back up the instant it popped. Well, after the drive I was heading down Kanan Dune Hwy at about 50mph in 5th gear and I would step on the gas and there would be NO power what so ever... I would let off the gas, and it would hold the RPM, then step on the gas and it wouldnt accellerate at all.. Finally I realized that when I stepped on the throttle, my car would shoot flames out of the exhaust... and not just a small little flame, but enough to see the flames in my rearview, when my exhaust dumped BEFORE my diff..

My exhaust setup is Hooker LT's, ORY, Cat, Borla XR1, turndown..

The motor is a stock LT1 with a cam and intake and exhaust. I already swapped the coil and ignition module, and all the plugs looked black and smelled of fuel. The left O2 is reading high mv's at around 900 consistantly, but thats probably due to it being soaked in fuel. I show no codes and there is nothing abnormal according to datamaster.

The car runs fine when it first fires up, then after it warms up a bit, it starts surging between 250rpm-1500rpm on its own, its quite bad, but will keep itself alive but gets progressivley worse.

Please Help!!!

Thanks guys! (thanks Injuneer in advance! )

 

I had a similar problem and throw a lot of parts at my car until the new ignition wires laid the final blow and the car ran fine again.

 

TTT Any other ideas? the wires are fresh and without defects.

 

I know there wasnt much interest in this thread, but for those that are having similar problems with their LT1's, the problem ended up being the opti. I swapped the opti as a last resort after changing the coil, Ignition Control Module and O2 sensors.

I used the new Accel opti and the car runs GREAT!! and on a side note, the opti feels a ton better internally than the stocker.