Hello Gents,

Been stalking the forums here awhile as I've owned several Rangers but never really needed to ask a question. Well that time has come.

Recently bought a 99 Ranger, 2.5L. Replaced fuel pump, transmission, clutch, starter, plugs/wires, coils etc.

More recently my Ranger has been revving to very high RPMs when I shift out of gear into neutral. I've also noticed that it will maintain a speed when in gear as well. It won't decelerate when I let off the gas it's like cruise control.

I replaced my IAC twice, once with a Hitachi brand and hen after some reading I bought a motorcraft IAC. The problem persists. I have checked high and low for vacuum leaks and cannot seem to locate one. My next plan of action is to replace the TPS. I have backed of the idle screw as well to no avail. Given the amount of posts on various forums I see this is a seemingly common issue. However nothing I've read has helped me this far.

Any input would be greatly appreciated. Would it be a good idea to just toss a new TPS at it?

Solved, coolant temp sensor