Won't Idle
Thread Starter
Intermediate
Joined: Mar 2005
Posts: 45
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Won't Idle
89, it will start but won't idle, dies right off if I let my foot off the gas. If I keep the foot on the gas it will idle ok but I'm smelling some gas. Seems to run ok if I rev it up a bit.
This happened very suddenly. It was running fine (no idle problems) and then I went out, started it, and suddenly had this idle problem.
Not putting up any codes.
Did a search and it seems to point to IAC.
I don't have a Helms (getting one). Is there a way to test if it is the IAC or not. I don't want to go on a wild goose chase of replacing components. For example does disconnecting the cable open the IAC or close it?
Thanks for any advice.
This happened very suddenly. It was running fine (no idle problems) and then I went out, started it, and suddenly had this idle problem.
Not putting up any codes.
Did a search and it seems to point to IAC.
I don't have a Helms (getting one). Is there a way to test if it is the IAC or not. I don't want to go on a wild goose chase of replacing components. For example does disconnecting the cable open the IAC or close it?
Thanks for any advice.
Last edited by jrockw01; Apr 1, 2005 at 07:56 PM.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
The problem could be due to a bad IAC but also due to a vacuum leak or MAF problem. Withough a scan tool it's hard to be sure.
If you jumper ALDL pins A & B (upper right) and turn the ignition on for 30sec or so the ECM will fully extend the IAC pintel. Then you can disconenct the IAC cable to keep the pintel extended, start the engine and set the base idle to 450RPM.
Some people say to disconnect the MAF and start the engine to test it but that didn't work for me. I had to install a used MAF from my '86 IROC to test mine.
Inspect all the vacuum hoses to see if any are cracked, off or broken.
Check fuel pressure after you turn off the ignition to see if you have any fuel leaks.
If you jumper ALDL pins A & B (upper right) and turn the ignition on for 30sec or so the ECM will fully extend the IAC pintel. Then you can disconenct the IAC cable to keep the pintel extended, start the engine and set the base idle to 450RPM.
Some people say to disconnect the MAF and start the engine to test it but that didn't work for me. I had to install a used MAF from my '86 IROC to test mine.
Inspect all the vacuum hoses to see if any are cracked, off or broken.
Check fuel pressure after you turn off the ignition to see if you have any fuel leaks.
