Ok, this is driving me nutz and I hope someone can help me figure it out. Before i start let me say that I have done a search and could not find an exact answer.

I have an 89 GTA 5spd w/ TPi w/ Vortec Heads, Scoggin Dickey Intake Base Plate, stock runners and stock plennum. Ever since I swapped the engine it would run but the idle would jump up and down from 500-800. Ive done everything I have read here about adjusting the iac and checking my tps voltage(.54), I have checked for vaccum leaks and recently installed new GM vortec intake gaskets.

To no avail has this problem gone away. I have even tried disconecting the MAF and running the engine to see if this was a problem, it wasnt.

I also have no codes. But if I sit at light the idle will continue to jump and sometimes it stalls the car.

Please someone help me i'm going insane. Is there something else I could check? Something I'm missing?

Thanks

 

Well, judging by your transmission you obviously had a 305 at one point. Did you swap over the electronic spark module, and knock sensor? These are different. Also are you using the 19lb 305 injectors? if so you need a new prom chip burned, or swap to 22 lb injectors.

If you are running a 305 prom, your timing curve is different and a few others. Your problem could be as simple as a silly chip.

 

Yes, the car did have a 305 at one point, it was swapped to a GMPP 350 w/ vortec heads. I have switched the injectors to brand new accell 22lb/hr injectors, and I have also bought a chip from tpi parts.

The chip I bought attaches to the old prom chip...it has updated info for the injectors, EGR delete, smog delete and is setup for a 350.

Also Ihave not changed the Electronic Spark Module or the knock sensor. Do you have part numbers for these? thanks