Thread: Issue, please help!!!

Hey guys, I have a 1997 grand prix GT. I top swapped it using a 2001 grand prix GTP top end. I have an odd issue going on. This happens ONLY at 160 degrees or hotter exactly, and it ONLY happens at an idle.

When I hit a red light at 160 degrees or hotter, my volts and RPM's drop at the same time together, then bounce back up and it idles a bit higher than it should.

I have replaced all of my sensors, and alternator, and battery. The PCM has been flashed at ZZP and it has been dyno tuned.

occasionally I'll be driving down the street and the engine will shut off on me, a check engine light comes on and it scans MAF sensor, I replaced the sensor twice now in case I bought a defective one.

Could this be a short in the wiring to the MAF? any help is appreciated! thanks!

Check for vac leaks, but the MAF can easily cause those issues.

Could be a short in the wiring for sure.

Would def. check the wiring. May have cut it during the swap. Did it have this problem before the tune?

ok awesome I will look into all your suggestions, thanks everyone.

I decided that it isn't a short because it is consistent, it happens every time at idle at 160 degrees or hotter

I did however notice that if I keep on the gas a tad bit it doesn't drop the volts and rpm's

so, I took it to zzp and they said its the adjuster bolt on the throttle cable, and that i need to turn it a bit to have it idle a bit higher, any suggestions on this? Thanks!

Do you have a cam in it? If not then I don't see why you would need to mess w/ the cable. That just seems strange to me. I would think the idle speed would be controlled by the PCM via electronics, not by having the cable hold the TB butterfly open a bit more.

I'm no tuning/electronics genious but I find it odd that once it starts getting up to temp it gets a bad idle. Almost makes me think a sensor is getting into closed loop and loses its mind somewhere or something in the PCM isn't quite right.