sr20det Irratic Idle

DriftRPS13 · 05-19-2005, 04:51 PM

My 240 is running like crap. It has an irattic idle (500-1500-500-1500) and is running rich. I pulled my plugs and they were all black. I cleaned them up and it ran ok for 5 min. and then it started to run like crap again. I think either I have a boost leak, oxygen sensor is bad or my MAF sensor is bad. Does anybody have any other ideas on things to check?

GotNismo? · 05-19-2005, 07:07 PM

if it was the maf it wouldnt respond to the throttle. um id say check that or maybe a vacuum leak, an exhaust leak would also make it run rich

TokyoDrifterxo7 · 05-25-2005, 12:07 PM

have you checked to see if the ECU is throwing out trouble codes? if it was a vacuum leak it would make it run lean because more air is entered in the engine than is sensed by the MAF. If it is a vacuum leak you wanna check for a whistling sound. When you took out your plugs did you notice any oil on them? you might also wanna check what color the exhaust smoke is. i think you might have worn valves or pistons, hopefully it's not that tho. listen for any un-usual noises.

SilverGhost · 05-25-2005, 06:36 PM

is it redtop? i have a redtop that was idling really bad, and wouldnt really rev, and ran rich as F$&%. i replaced the MAF and it started running decently. also, what is your timing set at? that makes a big difference as far as driveablility and power. i would check the MAF first and timing as well. Also an exhaust leak on turbo outlet pipe would cause a rich condition because your o2 sensor will read excess oxygen in your exhaust stream, so it will tell the ECU to increase injector pulse width to compensate, so it will run very rich. but if the leak is after the o2 sensor, it wont do anything to it really, just sound crappy. well, hope that helps man.

nwdriftking · 06-12-2005, 08:58 AM

If it is bouncing idle up and down it has to much air by pass. Try checking the idle set screw on the aivc between the intake manifold on cylinders 2 and three. there could be a few other things also but check that first. I've seen that be a prob more then a few times.

05-19-2005, 04:51 PM	#1
DriftRPS13 Registered User Join Date: Jan 2005 Posts: 37	sr20det Irratic Idle My 240 is running like crap. It has an irattic idle (500-1500-500-1500) and is running rich. I pulled my plugs and they were all black. I cleaned them up and it ran ok for 5 min. and then it started to run like crap again. I think either I have a boost leak, oxygen sensor is bad or my MAF sensor is bad. Does anybody have any other ideas on things to check?

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05-19-2005, 07:07 PM	#2
GotNismo? But officer i swear.... Join Date: May 2004 Location: New Orleans Posts: 234	if it was the maf it wouldnt respond to the throttle. um id say check that or maybe a vacuum leak, an exhaust leak would also make it run rich

05-25-2005, 12:07 PM	#3
TokyoDrifterxo7 Tokyo7even Join Date: Nov 2003 Location: SoCal Posts: 295	have you checked to see if the ECU is throwing out trouble codes? if it was a vacuum leak it would make it run lean because more air is entered in the engine than is sensed by the MAF. If it is a vacuum leak you wanna check for a whistling sound. When you took out your plugs did you notice any oil on them? you might also wanna check what color the exhaust smoke is. i think you might have worn valves or pistons, hopefully it's not that tho. listen for any un-usual noises.

05-25-2005, 06:36 PM	#4
SilverGhost touge sleepy-eye 180sx Join Date: Dec 2003 Location: CO Posts: 964	is it redtop? i have a redtop that was idling really bad, and wouldnt really rev, and ran rich as F$&%. i replaced the MAF and it started running decently. also, what is your timing set at? that makes a big difference as far as driveablility and power. i would check the MAF first and timing as well. Also an exhaust leak on turbo outlet pipe would cause a rich condition because your o2 sensor will read excess oxygen in your exhaust stream, so it will tell the ECU to increase injector pulse width to compensate, so it will run very rich. but if the leak is after the o2 sensor, it wont do anything to it really, just sound crappy. well, hope that helps man.

06-12-2005, 08:58 AM	#5
nwdriftking Registered User Join Date: Dec 2004 Location: Portland OR Posts: 19	If it is bouncing idle up and down it has to much air by pass. Try checking the idle set screw on the aivc between the intake manifold on cylinders 2 and three. there could be a few other things also but check that first. I've seen that be a prob more then a few times.