Emissions & Engine Control Systems
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Joined: Aug 2003
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From: Olympia, Washington
Emissions & Engine Control Systems
I have a 1999 Ford F150 4X4 with a 5.4 Liter V8 engine. The engine runs well except in the mornings when it is cool. The engine will start, then stall a number of times before it finally idles properly. The check engine light is not on. I took it to the dealer yesterday for dianosis and was told that the IAC valve was bad. I purchased an IAC valve at the dealer. I removed the IAC valve from the engine and check it with a digital multimeter. The resistance is 11.7 ohms, exactly the same as the new IAC valve.
It appears to me that the analysis done at the dealership may have been inadequate. I assume that the old IAC valve may be good based on the resistance check. I would appreciate help with this issue. I don't know if I should go ahead and install the new IAC valve or go back to the dealer for additional analysis.
ablecybernaut
It appears to me that the analysis done at the dealership may have been inadequate. I assume that the old IAC valve may be good based on the resistance check. I would appreciate help with this issue. I don't know if I should go ahead and install the new IAC valve or go back to the dealer for additional analysis.
ablecybernaut
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Joined: Mar 2003
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Emissions & Engine Control Systems
I do not know the specifics of your case, but I highly recommend to look at the possibility of an exhaust gas recirculation valve that remains partially open. This valve should be closed when the engine is cold. Sometimes with time carbon builds up around the seat of the valve consequently not closing when it should.
Good Luck!
Good Luck!
Thread Starter
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New User
Joined: Aug 2003
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From: Olympia, Washington
Emissions & Engine Control Systems
Thanks Abarreto for taking the time to respond. As an update, I replaced the ICV valve this morning and the problem is no longer present. The engine started immediately and continued to run without stalling. Evidently, even though the resistance is correct on the old ICV, there is carbon buildup or some other physical problem with the ICV that is causing the valve to not function properly. I replaced the EGR valve several weeks ago and didn't consider it to be causing the problem. The ICV valve is somewhat difficult to reach but I was able to remove it and install the new valve. Thanks again.
ablecybernaut
ablecybernaut
