I just bought a stock 89 Pontiac GTA. Off the line the car seems to have plenty of power, however, above 2500 rpms it doesn't pull like my friends stock 87 GTa, that should have 10 less HP. The exhaust smells a little funny, kinda rich and maybe like a bad converter, but the converter seems fine. The fuel injectors look like they may have been replaced. The guy i bought it from noticed the same problem. The motors sounds fine, no knocking and it revs up fine. Could it just be tune up parts or maybe tps and iac and timing adjustments?

What could be wrong, i plan on replacing the stock parts with the following parts to try to fix the problems and to increase the power.

-msd coil,
-msd cap and rotor,
-bosch plugs, and msd wires
-fuel filter and pcv and 02 sensor
-new exhaust system, catco cat, 80 series muffler, and 1 3/4 slp headers.
-bbk adjustable fuel pressure regulator.
-all new hoses and vacuum lines
-custom cold air intake.

Could it be something else?

 

Since you've resolved the question of restricted exhaust, you might still have weak spark, too much plug gap, no timing advance (EST connected?), poor fuel delivery, or a MAF output voltage problem.

What is your base timing?

 

i haven't checked the timing, that is what it seems to be, but shouldn't it adjust itself? It seems like ignition or a fuel problem. how can i check the Maf output voltage, what should it be. If the est is connected, is there a way to check to make sure it is functing porperly.

If there were any trouble codes, the SES light should come on right? I hope it is just "tune-up" related.