high idle and sputtering - TriStateTuners.com :: Home of Tristate Auto Enthusiast

JM Graphics · 01-20-2008, 04:01 AM

Car: GM S/C Pontiac Sunfire 2.4

Everytime i start the car cold or warm it idles VERY high, goes directly to 2k then either settles down to 900 where it supposed to be or studders and if it doesn't shut off it goes to 900 rpm.

The vac gauge is reading 20 which is what it is supposed to be, so no leaks there. I have changed the tps and iac about 2 times and never made a difference. I even unplugged the iac and it made not one difference, this happens when i put on diff sensors also, new and used.

Seems like everytime im cruising, let off the gas then hit it again softly it cuts out and my aem wideband goes to lean off the charts and then it picks back up.

Wondering if it could need re tuned or what. I'm running a slight tune that had a gm s/c re flash base.

malloyboy1 · 01-20-2008, 11:26 AM

any chance its some kind of idle air control valve?

05 mazda6s · 01-20-2008, 11:53 AM

clean MAF sensor?

Metalhedd · 01-20-2008, 11:56 AM

moisture in the distributer cap and rotor can cause cutting out too. that was the case with my car.

Cardriverx · 01-21-2008, 12:47 AM

Quote:

Originally Posted by JM Graphics

my aem wideband goes to lean off the charts and then it picks back up.

lean = spuddering. What is the wideband showing at idle?

Also, my car spudders alittle at cold start, but thats just cuz im running 305cc injectors without much tuneing..

SovXietday · 01-21-2008, 02:33 AM

How long has it been idling that high at cold start, since you got it reflashed? If so, that's you're problem.

Need more info. Has this just recently started or has it been since the ECU was reflashed.

JM Graphics · 01-21-2008, 07:56 AM

This has all of a sudden happened. Wondering if a bad MAP sensor could do this because im running a GM 2 bar MAP. I unplugged the battery for a hour and it started up doing the same stuff. The wide band is showing 11.2 at idle before closed loop which is rich as hell.

ScoobyNubieToo! · 01-22-2008, 09:28 PM

Could be a faulty 02 sensor?

01-20-2008, 04:01 AM	#1
JM Graphics Tri-State Training Wheels Join Date: Jul 2007 Location: MD Member #5311 My Ride: Dont worry about it. iTrader: (0)	high idle and sputtering Car: GM S/C Pontiac Sunfire 2.4 Everytime i start the car cold or warm it idles VERY high, goes directly to 2k then either settles down to 900 where it supposed to be or studders and if it doesn't shut off it goes to 900 rpm. The vac gauge is reading 20 which is what it is supposed to be, so no leaks there. I have changed the tps and iac about 2 times and never made a difference. I even unplugged the iac and it made not one difference, this happens when i put on diff sensors also, new and used. Seems like everytime im cruising, let off the gas then hit it again softly it cuts out and my aem wideband goes to lean off the charts and then it picks back up. Wondering if it could need re tuned or what. I'm running a slight tune that had a gm s/c re flash base.

01-20-2008, 11:53 AM	#3
05 mazda6s Tri-State Addict Join Date: Jun 2007 Location: Richboro, PA Member #5265 My Ride: 2003 Hyundai Tiburon GT iTrader: (0)	clean MAF sensor? __________________ PennState Class of '12

01-22-2008, 09:28 PM	#8
ScoobyNubieToo! Tri-State Post Whore Join Date: Sep 2005 Location: Williamstown Member #862 My Ride: WRB 2004 WRX Wagon with 07 STI Trans and Longblock inside! iTrader: (7)	Could be a faulty 02 sensor? __________________ 2004 WRX WRB Wagon with 07 STI Trans and Longblock inside! See my member's journal here: To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Sputtering when slowing down?	Erik	Engine Performance	10	05-23-2009 01:09 AM
VW- 95 2.0 Randomly stumbles at idle. between 800-1100 RPM's. Idle Control Valve?	Drftpretty	Engine Performance	0	03-15-2008 04:53 PM
Friends 04 Tiburon GT V6, high rev at idle. Help please.	05Accent	General Car Related Chat	10	01-23-2008 04:36 PM
sputtering exhaust?	ianblack06	Subaru Talk	8	08-29-2007 11:47 AM
Idle Issues (No longer holds idle)	naDintheHat	Audi / Volkswagen Talk	8	03-22-2007 01:24 PM

01-20-2008, 11:26 AM	#2
malloyboy1 Tri-State Addict Join Date: Jul 2007 Location: sellersville, PA Member #5438 My Ride: 05 subaru wrx iTrader: (2)	any chance its some kind of idle air control valve?

01-21-2008, 07:56 AM	#7
JM Graphics Tri-State Training Wheels Join Date: Jul 2007 Location: MD Member #5311 My Ride: Dont worry about it. iTrader: (0)	This has all of a sudden happened. Wondering if a bad MAP sensor could do this because im running a GM 2 bar MAP. I unplugged the battery for a hour and it started up doing the same stuff. The wide band is showing 11.2 at idle before closed loop which is rich as hell.