higher idle after long drive

[masphx]

Just got back from a weekend in Vegas. Truck was great there are back. It is about a 5-6 hour drive as I did not push the rig. When I got back into phx traffic at redlights I noticed my idle was around 1100 when clutch was in neutral. When I got home left it running for a min and the idle did not go down. Is this something I should be concerned about? Btw rig has 198200 miles on it. Normally rig will idle 500-700 rpm.

 

[Skidmarcx]

MIL on? Could be a vacuum leak? You can use a spray bottle with water to identify a leak by misting over the intake while idling... If it bogs the engine in any way that's a sign of an intake leak. Another possibility is if the computer thinks the operating temp is too cold and it's still in open loop... Is the temp gauge reading normal?

 

[masphx]

No cel. I even have it hooked up to an ultraguage. Besides the high idle nothing out of the ordinary that I can tell. When I drive it again will update this post if it idles high again. Maybe it was a fluke after a long drive?

 

[pluton]

One thing you can do is check to see the if throttle valve closes all the way at idle. On mine, the valve didn't close all the way, and I could, with moderate pressure, force it to close that last couple millimeters and then idle would be normal. Just another thing to hopefully rule out.

 

[Skidmarcx]

One thing you can do is check to see the if throttle valve closes all the way at idle. On mine, the valve didn't close all the way, and I could, with moderate pressure, force it to close that last couple millimeters and then idle would be normal. Just another thing to hopefully rule out.

True that I keep forgetting these trucks use a throttle cable