This has been a bit of an issue since I bought my 02 F150 4x4 last year, but it has magnified significantly in the last few days. The truck has a 4.2L engine with 5 speed tranny.

When I first got the truck, the idle would fluctuate between 1000 and 700 RPM. I changed the TPS, MAF, and CPS. I also cleaned the IAC. The problem pretty much disappeared completely, until a month or so ago, it started doing it again, just every now and then.

This past Friday, 12/4/15, it was doing it all of the time, and a new symptom was added into the mix. When I push on the clutch to change gears, or to come to a stop, the RPMs go up to 2000-2200, and stay there until I either let it out in the next gear, or come to a complete stop. If I do not touch the clutch at all, and just pop it into N, it does the same thing.

I have searched this forum, found a few possible answers, and have addressed them. My floor mat is nowhere near the gas pedal. My foot is nowhere near the gas pedal. The IAC has been changed to a new brand new one, the computer reset has been done, and I cannot detect and vacuum leaks by using the method of spraying starting fluid on the vacuum lines while running. I went through pretty much a full can by doing it over and over to be sure.

I'm at a loss on this one, and am hoping someone here has some insight. Thank you.