Car wants to Idle at 1000-1200 RPM initially,then bounces from 750-1000 for a while.After driving a while it idles fine, but fast for a few seconds after stopping.Is the IAC valve causing this?
Would too much or too little fuel pressure effect it?A friend told me I may need a switchable airflow sensor.Ever heard of this?
Any suggestions appreciated.
Motor is 350 with mild Compucam,Edelbrock Performer TBI,Adjustable Fuel Pressure Regulator,350 Truck Injectors,Turbo City Throttle Body,SLP Headers,Open Element Air Cleaner.
Thanks,
Rich

 

I had similiar experience after putting my engine together. You dont mention whether this has suddenly shown up or after mods have been made. Mine would also surge after taking foot off gas. What cured mine was a reprogrammed chip.
You might check for vacuum leaks if this is a new developement.

 

I recently installed a 300 HP 350 crate motor,custom chip and a bunch of other mods at the same time(headers,cat,intake,throttle body,adjustable pressure regulator,etc.)
Looked at the manual last night,says it could be vacuum leak (like you mentioned),IAC valve,Lean condition,etc.
Hopefully this weekend I'll have some time to test for leaks and maybe I'll swap out the IAC Valve, since I have another one.
The problem is intermittant. Sometimes it idles fine.Doesn't seem to matter if it's hot or cold.
Thanks for responding.
Anybody else have any other ideas?
-Rich-