I have a 90 iroc z 5.0 tpi. Recently has been stalling out. I changed out the tps and the idle control valve. My rpms have decreased since I changed it out. I have the self adjusting tps so I can’t adjust it. It turns on fine but sometimes I put it in reverse and just dies. Or when I’m about to get to a stop my rpms go below 500 then resumes and wants to stall. I checked for codes and it threw a 22. Could it possibly be a vacuum leak? The tps I installed on it was from auto zone. So what ived read these Camaros can be picky with the tps. So I ordered a tps from ac delco brand.

 

I would check for vacuum leaks to start. What does it idle at in park?

 

it idles at around 600-700 rpm. But when I switch it to drive or reverse it dies

 

so ive notice that when I keep switching it from park to reverse or drive the rpms keep dropping. So if it was idling at 6-700 rpm, I would reverse or switch it to drive then back to parking it would idle lower. Can’t seem to figure out what’s going on.

 

Maybe TPI is different, but 600-700 RPM in Park sounds awfully low. I have a '91 305 TBI, and IIRC the recommended idle speed for my car in Drive is 650 RPM. My car idles rough at anything below that, and wants to stall at or below 500.

Did you adjust your new IAC valve when you installed it?

 

yes I did adjust the IAC valve, just checked the tps voltage and it’s good. I just can’t figure out what the problem is. It only does it when I change to reverse from parking or from parking to drive. It’ll jump below the 500 rpm line and go back to 600-700 rpm and sometimes stall when it does the jump. Or when I’m going to come to a stop it does it. The only code is throwing is a 22, tps low voltage.