insane rpms

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Dec 4, 2008 | 02:12 PM

bansheeduner

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From: Scottsdale, AZ

insane rpms

i have an 01 f-150 5.4l with a 130k on it when i start it in the morning and the truck reaches 146-176 degrees the rpms go up and down at a stand still in neutral park or drive but once the truck reaches 198 degrees its fine please help i have no idea whats wrong it throws no codes what so ever

Dec 4, 2008 | 02:34 PM

KingRanchMan02

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From: Louisville, Kentucky

You could have a dirty IAC valve or a dirty MAF. Do you have a oiled air filter such as a K&N on it? Recharged the filter lately? Good luck!

Dec 4, 2008 | 03:03 PM

bansheeduner

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From: Scottsdale, AZ

yes i have cleaned and done every type of maitnence

Dec 4, 2008 | 03:28 PM

KingRanchMan02

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From: Louisville, Kentucky

If I am not mistaken, the only two things that can effect engine RPM at idle are the IAC and the TPS. Neither of these are routine maintanence items.

Dec 4, 2008 | 03:50 PM

bansheeduner

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From: Scottsdale, AZ

whats an iac

Dec 4, 2008 | 04:06 PM

KingRanchMan02

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From: Louisville, Kentucky

IAC = Idle Air Control valve. TPS = Throttle Position sensor. The IAC, located on the back of the intake manifold near the throttle body, controls the amount of air that the engine gets when the throttle is closed. A sticky valve will cause the idle to be erratic and can even cause stalling or failure to start.