I have a 87 Trans Am with a Ls1/t56. It has all of the bolt ons with a TR230/224 cam. I do not have a tune. Here is my problem. The car is running like crap. It seems to run good until the car warms up, then it idles lower and backfires (sometimes very badly) and sometimes dies. I am not throwing any codes.

I have the EGR, AIR, Evap, Rear O2s, and all of that fun stuff tuned out. Could this be becuase of the open headers? I am using the LS1/Third Gen headers from Hawks Third Gen with no piping added on, just straight headers.

I also took the car around the block. Seemed to not have the power it should and ran worse as the car heated up.
The car runs and idles good if the engine is cold.

 

Well, when the car is cold, it's in open loop mode which the car will run different than closed loop mode. With any type of cam swap, you need to get a tune on it, or it will continue to run like crap.

 

I know I need a tune, but would the car really run as bad as it is?

 

If it's feeding more air than fuel in the car, and the PCM isn't compensating for the cam lift and duration, yes.

 

Well the open headers arent helping. Mine ran like crap until I got the exhaust on it. Same issue you are having, it seemed ok when it was cold but not when it warmed up.

 

get it tuned then get back to us.

 

+1 on the tune...

 

All good now! Didn't doulble click the wires on the coils.