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View Full Version : Idle wont drop down - intermittent


rwassman
06-20-2010, 11:32 PM
I've got '95 Prostar with the Chevy and for about the last year it sometimes idles at 1200 rpms and wont drop down regardless of how long I let it run or if I punch the accelerator in neutral and take it up to 2000+ rpms - it still wont go below 1200. But most other times it will start and will drop down to 650 rpms like it should. 80% of the time when I start it it works the way it should then 20% of the time I have to turn it off and restart it. Sometimes it will work on the first restart and sometimes it will take 3 or 4 restarts before it idles then drops. This is completely random and doesn't matter if the engine is hot or cold.

1redTA
06-21-2010, 06:54 AM
Sounds like the idle air control valve, IAC. Probably needs the carbon cleaned of it

ecproductions143
06-21-2010, 07:17 AM
Sounds like the idle air control valve, IAC. Probably needs the carbon cleaned of it

there located on the metering block. Vince from skidim says to tighten in all the way then back out 1 1/2 turn then make some adjustments from there

JimN
06-21-2010, 07:52 AM
I've got '95 Prostar with the Chevy and for about the last year it sometimes idles at 1200 rpms and wont drop down regardless of how long I let it run or if I punch the accelerator in neutral and take it up to 2000+ rpms - it still wont go below 1200. But most other times it will start and will drop down to 650 rpms like it should. 80% of the time when I start it it works the way it should then 20% of the time I have to turn it off and restart it. Sometimes it will work on the first restart and sometimes it will take 3 or 4 restarts before it idles then drops. This is completely random and doesn't matter if the engine is hot or cold.

Slide the collar back on the throttle cable and remove it from the throttle lever. If it goes back to normal idle speed, it may have stretched or is binding. Otherwise, if you have Perfect Pass or something like it, dis-engage that.

If you remove the IAC, don't turn the key to ON with the IAC out- the pintle will come out and forcing it back in will damage it, making it useless.