High idle

NOVASS2007 · 06-28-2009, 06:16 AM

I have an 89 chevy corsica with a very high idle it has a throttle body fuel injection system. I have already checked the TPS and it shows proper operating voltage, (.45 to 1.25 at idle). I'm thiking the IAC may be bad it was showing 53 oahms on a to b and c to d terminials any ideas what to check next?

**mack1** · 06-28-2009, 08:39 AM

Hi NOVASS2007 and welcome to TSF,

You might have a vaccuum leak. If you don't have a vaccuum gauge, you might just sequentially unplug the hoses and hold you finger over the inlet for testing. (thats the old fashion way, but works sometimes).

Check the PCV, sometimes they stick open causing excess crankcase air and vapors to enter the engine intake.

On multi port fuel injection systems, there is an idle control valve. Not sure the throttle body ones have this valve or not. If so, check it to make sure it is working.

Let us know what you find.

Best regards,
Mack1

06-28-2009, 06:16 AM	#1 (permalink)
NOVASS2007 Registered User Join Date: Jun 2009 Posts: 1 OS: xp	High idle I have an 89 chevy corsica with a very high idle it has a throttle body fuel injection system. I have already checked the TPS and it shows proper operating voltage, (.45 to 1.25 at idle). I'm thiking the IAC may be bad it was showing 53 oahms on a to b and c to d terminials any ideas what to check next?

06-28-2009, 08:39 AM	#2 (permalink)
mack1 TSF Articles Team Join Date: Nov 2007 Location: Texarkana, Texas Posts: 1,245 OS: xp sp3 My System	Re: High idle Hi NOVASS2007 and welcome to TSF, You might have a vaccuum leak. If you don't have a vaccuum gauge, you might just sequentially unplug the hoses and hold you finger over the inlet for testing. (thats the old fashion way, but works sometimes). Check the PCV, sometimes they stick open causing excess crankcase air and vapors to enter the engine intake. On multi port fuel injection systems, there is an idle control valve. Not sure the throttle body ones have this valve or not. If so, check it to make sure it is working. Let us know what you find. Best regards, Mack1 __________________ "If you like yourself others will like you also" me "Don't drink downstream from the herd" Will Rogers Submit New Articles Here