HELP Won't idle

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Sep 29, 2007 | 10:34 PM

big red c222

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From: West Chester Pa.

HELP Won't idle

I'd been driving around for the past month with my trouble light on. I got used to seeing it for the past 3 years or so, every once in a while it would come on, I'd read the code. It was always the MAF sensor got oil on it from my after market air filter. (apparently very common) I'd clean it, good as new. A few days ago I did it again for about the 5 th time since I've owned it. I got into the computer with my Hypertech power programmer to clear the code. I changed some of the settings in the program. Now the truck has an intermittent problem where the idle drops so low it stalls out. If I put it in neutral and let off the gas super slow it will idle at about a couple hundred rpm. Usually if I turn the truck off and wait a few min. When I restart it, it runs fine, but then within 5-10 min. it wants to stall when I come to a stop. I reprogrammed everything back to factory settings, nothing, then I bought a new (remanufactured) Mass air flow sensor. It didn't change anything. I guess I have to give up and make an appointment, unless someone can help? It's a 2004-4X4-5.4

Sep 30, 2007 | 08:39 AM

black04lariat

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From: Greenville, SC

Search for Idle Air Controller (IAC) or Throttle Position Sensor (TPS). If I had to guess it would be one of those.

Sep 30, 2007 | 09:14 AM

big red c222

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From: West Chester Pa.

I guess I should check them out. I don't know why what did would cause them to go. That's me being pig headed. I keep thinking it's the program. Can you an intermittent problem with a computer program ? Now that I think of it, my 91 was doing something very similar and it was the IAC. That's a 16 year old truck this one is only 3 years.

Sep 30, 2007 | 09:21 AM

marktfp

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i have a 98 and the same problem. it was the iac valve. you can take it off and clean it if it works then you can wait or replace it

Sep 30, 2007 | 09:23 AM

big red c222

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From: West Chester Pa.

Quote:

Originally Posted by marktfp

i have a 98 and the same problem. it was the iac valve. you can take it off and clean it if it works then you can wait or replace it

I'm going to try that right now. Thanks.

Sep 30, 2007 | 10:48 AM

big red c222

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From: West Chester Pa.

Just checked the books because of the drive by wire, there is no IAC, there are 2 TPS. I took the air filter tube off. The throttle body is very dirty, to the point I think it's not letting the plate seat properly. The book says the throttle body is coated with a special film, and is not able to be cleaned. I'm supposed to just replace it???. I'm going to clean it with a tooth brush, no carb cleaner.

Sep 30, 2007 | 01:25 PM

big red c222

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From: West Chester Pa.

YEE HA I fixed it. I had some citrus based de greaser. I cleaned the throttle body real good. It runs great. I drove it around for about an hour. Idling great. I didn't realize they got so dirty, being that no gas passes thru it.