Uncontrolled Reving

[Explorer1958]

Hello
My 97 4.0 OHV manual has developed a annoying proplem. Starts and idles OK, moves away OK and then as its heating up and any time after that, it revs to 3000rpm. Could stay there for a couple of seconds to 30 seconds before dropping back to idle. It won't rev up by itself, only does it after I push down on the accelerator pedal under load. Is happening more and more. A quick look under the hood reveals nothing obviously wrong. Any one had similar out there?.
Thanks

 

[Explorer1958]

Solved my own problem after reading various threads including the good gear from Glacier991. Removed the IAC and gave it a clean and freed it up and now she goes better than any time in the past. Thanks Explorer Forum.

 

[foxy]

G'Day . Mate do you have a overheating problem as well ? I also cleaned my IAC valve but then found my thermostat was RS .I replaced it with a cooler one and it fixed it all. Cheers Foxy

 

[Explorer1958]

Uncontrolled reving and O/Heating

Didn't effect the temp at all after giving the IAC the treatment. But did solve a previous O/Heating issue by getting the Radiator cleaned out internally. Lesson, Don't put one of those additives in the cooling circuit to seal up a leaking welsh plug, its gunna clag your radiator right up and yes I did replace the thermostat with a cooler temp one but since its winter "Down Under" now Ive got the standard one in at the moment and will probably leave it there.

See ya