Please Help,
I want the power in my 1989 Trans Am GTa to come back. This car has had extensive work over the last two yrs. Replacement parts have been, MAF, ECM, TPS, Cats,injectors and pressure regulator, plug wires, cap, rotor, ignition coil, ignition module,oxygen sensor,temp sensor,Hypertech chip and thermoswitch,ignition pickup and new long block and transmission. Problem is after the new injectors and pressure regulator and long block was installed the car runs like it has about 150 horsepower not 250, it will not climb above 4800 RPM's and takes its time getting there. It has 45psi fuel pressure and will not hardly even spin the tires. I know what this car ran like when I bought it but it has been to three shops, two of which say there is nothing wrong with the car the other said the timing was not advancing but that they could not fix. I have spent $5000 on this car already and not prepared to spend much more. Occasionally it will throw code 32 but the shops told me it was EGR related and would not hurt the power of the car. I have done extensive research and work myself on this car because no one else could help me. The car idles good and drives well as a grandma car but a Grand Am could dust it in a kickdown race on the highway. Any Ideas anyone.

 

This is a guess but I would suspect the new long block assembly that was installed. Was the long block assembly a roller cammed TPI replacement engine or was it a generic long block 350. My thought was that the original engine was replaced with a 350 TBI engine for a truck or some other application.

 

MAn it sound like you and I have he same problem....My supercharged GTA is running worse times than a honda civic...I have diacom plus software To diagnose that kind of stuff...I live in cincy...Not far from hamilton...I could help you out with live readouts of ecm function....That will help you to better solve what the problem is if its computer related... Found out real quich half of my problem was Knock retard...Before using the software I had NO CLUE...

 

It sounds like at least two different things to me. One, you could have been f*ucked and they put a different long block in instead of the original l98. Second, sounds like a problem i went with when i bought my stock iroc back. It was my ignition modual and a couple of vacum lines where disconected along with my TIMMING. If i was in you shoes I would advance the timmine. Once i changed those 3 things the car ran like new and is a blast to drive. Post a new topic if youd dont know how to time the car and i will be happy to reply. good luck
Bob

 

Hmmn, just wild guessing here...but EGR code could be set because of too much backpressure on/in the exhaust...coupled with a lack of power could indicate a restricted exhaust...i/e plugged cat, plugged muffler, crushed pipe. Might want to check vacuum at idle and compare to vacuum at 2500 rpms..or check backpressure through O2 sensor hole. Again, justa WAG.

 

Welcome to thirdgen.org

 

I never even thought about that, (pluged exhaust) that is a good theiry. A pluged cat or muffler could be the problem. I took my emissions stuff off and cat before i found my problem, but it still helped. That is a good possibility that is to much back pressure, good luck.
Bobby

 

Sorry I miss represented the long block, the engine was rebuilt due to a spun rod bearing[new crank and recondition rod and overhaul on the rest ,same cam). I did not mention that in cool weather conditions its seams to load up bad until it warms up[chugs when it first starts].

 

NotsobadGTA--My iroc "chugs" on a cold start also, i think all cars do in some sort of way. My car hates cool starts. Good luck with your fix
Bobby

 

Changed cats today one was bad, that didn't fix it though. took muffler off and car tached right up to 6000 again.I guess half the stuff from the cat went into the muffler. Thanks for the tip, all the power is not back yet but it is close and I am sure with some more tuning I can get it back to its old self. So many people have monkeyed with this car trying to diagnose other things are probably a little off.