I am having a bad idling problem

BIGDATOWN · 05-04-2011, 12:14 PM

Ok. When the car is cold and been sitting for atleast an hour or over night the car will crank and idle perfectly! Now when the car has gotten warmed up for awhile and you turn the car off, it will not crank and stay running on its own. Its like the throttle stop to set your idle has completly broken off. The car seems to idle smoothly once you give it gas to hold a idle and will drive just fine. Now once you keep holding it at about a 800 rpm idle, you feel something seem like it went back to normal and the car will shoot up in idle until you let off the gas pedal, then it will idle correctly unless you turn the car off again, and then it starts all over unless sitting for awhile.

Sorry for the book, but I am really unsure as to how to figure out the problem. I tried forcing the car to open loop when it does it, changing to a different tune, all with no change.

Please HELP!

I also made a data log of what its doing if someone would like to look at it.

The car is a 95 mustang gt 5.0 Only mods are a c&l 76mm cal for 19's

QWKSNKE · 05-04-2011, 05:10 PM

It is the meter.

Do you have it hooked to a stock airbox or open filter?

grabbinandstabbin · 05-04-2011, 08:09 PM

it could be the IAC sticking too. had the same problem on my 94. took it off and clean it. solved the problem.

QWKSNKE · 05-04-2011, 08:47 PM

yeah you could try the IAC procedure first. If that don't fix it then either ditch the C&L meter or put the stock airbox back on (if you are not running it)

Back when I dabbled in retailing parts I was a C&L dealer. We quit promoting and selling any of their products within a few months because nearly every meter we sold people had problems with. Personally I don't recommend C&L products to anyone. But I have read where there 76mm kits pretty much cannot be run without the stock airbox because of this very problem you are experiencing.

BLOWN95GT · 05-05-2011, 04:54 AM

Have you tried cleaning the mass air meter yet? A lot of times the wires get caked up with the oil off of the air filter and can't get a good reading wich will cause idle surge especially if it's a new filter. I would also try what the others said and clean the iac, do you still have the stock meter housing? If somi guess you could swap it back out and see if it fixes it. I personally have never had a problem with a c&l meter making a car surge and that's all I ever ran before going blow thru, but it's worth a shot.

Sendero · 05-05-2011, 06:47 AM

Does outside temperature affect the idle? Example: If it's 90*'s outside it won't idle right for the first 90 seconds or so after sitting overnight. If it's 50*'s outside it will crank and idle fine after sitting overnight.

Lee, you know where I'm going with this. These issues are pretty similar.

grabbinandstabbin · 05-05-2011, 07:52 AM

true it could also be the intake air temp sensor.

BIGDATOWN · 05-05-2011, 08:39 AM

I think I have it narrowed down to a sticking egr valve. It did this a few times before I went to c&l. And before I even bought this tuner. I actually turned the egr off in my tune now and gonna run it until it gives me another problem. If it doesn't I have my answer. And the temp didnt have anything to do it either. When I logged the problem the ACT was reading 104-106.

05-04-2011, 12:14 PM	#1
BIGDATOWN Senior Member Join Date: Aug 2010 Posts: 221	I am having a bad idling problem Ok. When the car is cold and been sitting for atleast an hour or over night the car will crank and idle perfectly! Now when the car has gotten warmed up for awhile and you turn the car off, it will not crank and stay running on its own. Its like the throttle stop to set your idle has completly broken off. The car seems to idle smoothly once you give it gas to hold a idle and will drive just fine. Now once you keep holding it at about a 800 rpm idle, you feel something seem like it went back to normal and the car will shoot up in idle until you let off the gas pedal, then it will idle correctly unless you turn the car off again, and then it starts all over unless sitting for awhile. Sorry for the book, but I am really unsure as to how to figure out the problem. I tried forcing the car to open loop when it does it, changing to a different tune, all with no change. Please HELP! I also made a data log of what its doing if someone would like to look at it. The car is a 95 mustang gt 5.0 Only mods are a c&l 76mm cal for 19's

05-04-2011, 08:47 PM	#4
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	yeah you could try the IAC procedure first. If that don't fix it then either ditch the C&L meter or put the stock airbox back on (if you are not running it) Back when I dabbled in retailing parts I was a C&L dealer. We quit promoting and selling any of their products within a few months because nearly every meter we sold people had problems with. Personally I don't recommend C&L products to anyone. But I have read where there 76mm kits pretty much cannot be run without the stock airbox because of this very problem you are experiencing. __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

05-05-2011, 06:47 AM	#6
Sendero Im gonna show her my... Join Date: Dec 2004 Location: Somewhere providing FREE tech support. Posts: 4,269	Does outside temperature affect the idle? Example: If it's 90's outside it won't idle right for the first 90 seconds or so after sitting overnight. If it's 50's outside it will crank and idle fine after sitting overnight. Lee, you know where I'm going with this. These issues are pretty similar. __________________ I heard it on the internet, so it must be true. "I believe that a person's moral compass can be determined by how he references free men the right to defend themselves." T. Nugent "An armed society is a polite society. Manners are good when one may have to back up his acts with his life." R. Heinlein "Never argue with an idiot. They drag you down to their level, then beat you with experience." -Unknown

05-04-2011, 05:10 PM	#2
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	It is the meter. Do you have it hooked to a stock airbox or open filter?

05-04-2011, 08:09 PM	#3
grabbinandstabbin Member Join Date: Dec 2008 Location: UCLA Posts: 68	it could be the IAC sticking too. had the same problem on my 94. took it off and clean it. solved the problem.

05-05-2011, 04:54 AM	#5
BLOWN95GT Senior Member Join Date: Mar 2010 Location: Oneonta, Alabama Posts: 401	Have you tried cleaning the mass air meter yet? A lot of times the wires get caked up with the oil off of the air filter and can't get a good reading wich will cause idle surge especially if it's a new filter. I would also try what the others said and clean the iac, do you still have the stock meter housing? If somi guess you could swap it back out and see if it fixes it. I personally have never had a problem with a c&l meter making a car surge and that's all I ever ran before going blow thru, but it's worth a shot.

05-05-2011, 07:52 AM	#7
grabbinandstabbin Member Join Date: Dec 2008 Location: UCLA Posts: 68	true it could also be the intake air temp sensor.

05-05-2011, 08:39 AM	#8
BIGDATOWN Senior Member Join Date: Aug 2010 Posts: 221	I think I have it narrowed down to a sticking egr valve. It did this a few times before I went to c&l. And before I even bought this tuner. I actually turned the egr off in my tune now and gonna run it until it gives me another problem. If it doesn't I have my answer. And the temp didnt have anything to do it either. When I logged the problem the ACT was reading 104-106.