92 Camaro RS 5.0 TPI (88 wiring harness), I reset the idle this past weekend to around 600 rpm, drove it for a while and it ran great. I let it sit overnight, and when I started it the idle jumped up to 2000ish and would not come down. Whenever i put the clutch it it goes right back to 2000. I just unplugged the iac to see if the idle was any different and it wasnt. I even turned the idle set screw on the throttle body back as far as it could go and the engine wont come below 1400 rpm now. Any thoughts?

 

To add to my last post, I just put a jumper on the aldl and got no codes, and I can feel the iac ticking away so I know thats not it. I did just replace me throttle position sensor and havent been able to get the signal voltage above 0.11v and I'm not sure why.

 

Check for something other than the throttle plates admitting air (a.k.a., vacuum leak). Other than the usual suspects such as hoses, gaskets, injector o-rings, and PCV valve, you might also want to investigate the brake booster, EGR valve, and less common sources.

When the leak has been located and repaired, go back and set the throttle minimum air position properly, and don't try to set the idle RPM with the TB stop screw. Once the minimum air position is set, verify the 5V logic supply to the TPS and see if the closed throttle voltage can be set correctly and the signal tracks the TB as it should to at least 4.5V.

 

What should the voltage be at the maf? 5v?

And I don't hear any whistling from any of my vacuum lines, could I still have a leak? Is there a safe way to test if there is one?

 

I haven't been able to correct the idle but I managed to get it a little lower so I could drive it. However, I did just recently get error code 54, could this have something to do with my high idle? If the egr solenoid was bad, how would I know?