Lousy idle?

KiltedBanshees93GT · 09-10-2005, 11:43 AM

OK folks, I think I've already covered most of the basics on this one:
Car:93gt, pretty much bone stock.
Symptoms: The car started idling a little rough two days ago, got worse yesterday. Also noticed that when you come off the gas, the idle doesent drop all the way back down to normal, it holds around 1k-1200 for a second or two, then drops again.
With the car just sitting, the idle will slowly drop, then stumble and occasionally stall (but not always,some times it'll seem to just teeter on the brink)
You can also smell gas in the exaust

First thought was that it fouled a plug, (burns oil on 2 cyls) I check the usual cylinders, and indeed, one was looking pretty crappy, and the other was borderline. Replace them, cars's still doing it.
So far I've: Checked all the other plugs, all ok, replaced cap,rotor, wires,and coil (I just did the coil on general principal, since as far as I know its original)
Run throttle body cleaner through
Checked timing (with the spout in it fluctuates with the idle, with it out its at a solid 10deg. Also noticed that if I give it gas with the spout out, it seems to be running really rich, I can hear popping and occasional backfiring in the exaust)
Checked Vacuum, steady 13-14 lbs,
Ran car with IAC unhooked, no noticible change,
Ran car with MAF unhooked, car died after a few seconds
(The MAF was also cleaned about 3 weeks ago, but I havent pulled it out again)
I cant check the TPS, since i just found out that my multi meter is apparently dead

KOER I get 12,94,34. (I just got my reader a few weeks ago, and its had the 34 I just havent had a chance to screw w/ the egr yet)

Any ideas? Bad injector? Stuck open maybe?
Thanks
J

Also, maybe unrelated, but maybe not, I also noticed a new noise coming from the engine, sounds like pass side, cant be any more specific, it sounds linda like a "tsk tsk" but seems to come and go(?)....
__________________

Dark_5.0 · 09-10-2005, 11:55 AM

Sounds like a bad IAC valve to me. Its on the front of the throttle body and shaped like a cylinder. Remove it and clean it then if it still does it replace it.

KiltedBanshees93GT · 09-10-2005, 12:01 PM

If the IAC was bad, shouldn't disconnecting it have cleared the problem up?
I'm gonna go check it anyway tho...

KiltedBanshees93GT · 09-10-2005, 12:34 PM

Well, cleaning it didn't help. It only had moderate carbon buildup, but I took the whole assy off, removed the solenoid/sensor end, and hosed the crap outta it with TB cleaner...
Would the whole thing or just the valve part need to be replaced?

GhettoPop · 09-10-2005, 05:29 PM

http://members.tripod.com/sparkplugs/idle.htm

http://www.50tech.com/articles/displ...p?catid=8&id=4

http://www.50tech.com/articles/displ...?catid=9&id=10

~The Jester~ · 09-10-2005, 10:58 PM

Quote:

Originally Posted by Dark_5.0

Sounds like a bad IAC valve to me. Its on the front of the throttle body and shaped like a cylinder. Remove it and clean it then if it still does it replace it.

Yep! Idle Air Motor...........

KiltedBanshees93GT · 09-11-2005, 08:57 AM

Is there any way I can test to verify its hosed before popping $70 for a new one?

BTW, TPS was sitting at .93, I managed to get it up to .964, but thats about as high as it'll go.

Falcons Talon · 09-15-2005, 02:46 PM

You have to dremel out the screw holes a little so that you can twist the TPS a little more.

09-10-2005, 11:43 AM	#1
KiltedBanshees93GT Registered Member Join Date: Jun 2000 Location: Pigeon Forge Tn Posts: 611	Lousy idle? OK folks, I think I've already covered most of the basics on this one: Car:93gt, pretty much bone stock. Symptoms: The car started idling a little rough two days ago, got worse yesterday. Also noticed that when you come off the gas, the idle doesent drop all the way back down to normal, it holds around 1k-1200 for a second or two, then drops again. With the car just sitting, the idle will slowly drop, then stumble and occasionally stall (but not always,some times it'll seem to just teeter on the brink) You can also smell gas in the exaust First thought was that it fouled a plug, (burns oil on 2 cyls) I check the usual cylinders, and indeed, one was looking pretty crappy, and the other was borderline. Replace them, cars's still doing it. So far I've: Checked all the other plugs, all ok, replaced cap,rotor, wires,and coil (I just did the coil on general principal, since as far as I know its original) Run throttle body cleaner through Checked timing (with the spout in it fluctuates with the idle, with it out its at a solid 10deg. Also noticed that if I give it gas with the spout out, it seems to be running really rich, I can hear popping and occasional backfiring in the exaust) Checked Vacuum, steady 13-14 lbs, Ran car with IAC unhooked, no noticible change, Ran car with MAF unhooked, car died after a few seconds (The MAF was also cleaned about 3 weeks ago, but I havent pulled it out again) I cant check the TPS, since i just found out that my multi meter is apparently dead KOER I get 12,94,34. (I just got my reader a few weeks ago, and its had the 34 I just havent had a chance to screw w/ the egr yet) Any ideas? Bad injector? Stuck open maybe? Thanks J Also, maybe unrelated, but maybe not, I also noticed a new noise coming from the engine, sounds like pass side, cant be any more specific, it sounds linda like a "tsk tsk" but seems to come and go(?).... __________________ __________________ ____________ '66 Mustang Coupe- AKA "Lenore" on disability for a (long) bit '93 GT Mostly stock AKA "Fawkes" Rice Haters Club Member #239 "I find your lack of faith...disturbing." "Every normal man must be tempted at times to spit on his hands, hoist the black flag, and begin to slit throats." H. L. Mencken

09-10-2005, 11:55 AM	#2
Dark_5.0 Registered Member Join Date: Apr 2001 Location: Staging lane Posts: 4,337	Re: Lousy idle? Sounds like a bad IAC valve to me. Its on the front of the throttle body and shaped like a cylinder. Remove it and clean it then if it still does it replace it. __________________ 92' LX-Big brakes, Lots and lots of suspension, GT40X heads, Ported cobra intake, stock cam, Vortech SC trim. 00' Lightning-Stock 88'CRX-13 second ego killer

09-10-2005, 12:01 PM	#3
KiltedBanshees93GT Registered Member Join Date: Jun 2000 Location: Pigeon Forge Tn Posts: 611	Re: Lousy idle? If the IAC was bad, shouldn't disconnecting it have cleared the problem up? I'm gonna go check it anyway tho... __________________ ____________ '66 Mustang Coupe- AKA "Lenore" on disability for a (long) bit '93 GT Mostly stock AKA "Fawkes" Rice Haters Club Member #239 "I find your lack of faith...disturbing." "Every normal man must be tempted at times to spit on his hands, hoist the black flag, and begin to slit throats." H. L. Mencken

09-10-2005, 12:34 PM	#4
KiltedBanshees93GT Registered Member Join Date: Jun 2000 Location: Pigeon Forge Tn Posts: 611	Re: Lousy idle? Well, cleaning it didn't help. It only had moderate carbon buildup, but I took the whole assy off, removed the solenoid/sensor end, and hosed the crap outta it with TB cleaner... Would the whole thing or just the valve part need to be replaced? __________________ ____________ '66 Mustang Coupe- AKA "Lenore" on disability for a (long) bit '93 GT Mostly stock AKA "Fawkes" Rice Haters Club Member #239 "I find your lack of faith...disturbing." "Every normal man must be tempted at times to spit on his hands, hoist the black flag, and begin to slit throats." H. L. Mencken

09-10-2005, 05:29 PM	#5
GhettoPop Gimme a Drink! Join Date: Dec 2002 Location: NYC Posts: 694	Re: Lousy idle? http://members.tripod.com/sparkplugs/idle.htm http://www.50tech.com/articles/displ...p?catid=8&id=4 http://www.50tech.com/articles/displ...?catid=9&id=10 __________________ 1990 GT,stock T-5,K&N w/o air silencer,March underdrives,FMS wires,timing@14*,PA Perf 130amp alt,Steeda Tri-Ax Shifter,Steeda adj quadrant/clutch cable/firewall adj,Centerforce II clutch,o/r x-pipe,Magnaflow SS catback,g-load brace, subframes,Bilstein struts/shocks,Autometer gauges, 136k and running strong!

09-11-2005, 08:57 AM	#7
KiltedBanshees93GT Registered Member Join Date: Jun 2000 Location: Pigeon Forge Tn Posts: 611	Re: Lousy idle? Is there any way I can test to verify its hosed before popping $70 for a new one? BTW, TPS was sitting at .93, I managed to get it up to .964, but thats about as high as it'll go. __________________ ____________ '66 Mustang Coupe- AKA "Lenore" on disability for a (long) bit '93 GT Mostly stock AKA "Fawkes" Rice Haters Club Member #239 "I find your lack of faith...disturbing." "Every normal man must be tempted at times to spit on his hands, hoist the black flag, and begin to slit throats." H. L. Mencken Last edited by KiltedBanshees93GT; 09-11-2005 at 09:14 AM..

09-15-2005, 02:46 PM	#8
Falcons Talon T.P.M. President Join Date: May 2002 Location: Brownsville Posts: 265	Re: Lousy idle? You have to dremel out the screw holes a little so that you can twist the TPS a little more. __________________

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