My 2001 Ranger 2.5L 5 speed manual, recently started having high(3200 rpm's) when ever I start the engine then gradually settle down to 900 rpm's within 10 or 15 seconds. I've checked for vacuum leaks, none.
I've replaced with new IAC valve & TP sensor. Also cleaned throttle body plate & MAF sensor. No change. Anyone with an idea, incite or experience, what may be causing this?

 

Hey, man…
sorry that your having issues, that’s sucks.

The normal Startup RPM before it settles around 850-900 rpms should be 2000-2100 rpms.

4 questions:
Did you replace those 2 sensors before or after the problem came up?
Have you scanned the computer for codes, if so what did it give you?
Does the engine rev up real quick and back down when you push the clutch to shift sometimes?
Where did you get your TPS and IAC from?

Last Thing, on the 2.5Ls there is an Anti-Diesel Screw located just behind the ice shield for the throttle cable, it’s a little screw that takes a Flathead screwdriver and has a spring under the head. That screw holds the throttle plate open. Now someone can correct me if I’m wrong, If the throttle plate is open too much then that will cause rpm surges on startup. So you might be able to Back off the screw a little to drop the revving. Tighten to give more throttle and loosen to give less.

Sorry for not seeing your 5 days ago, I don’t log in everyday.

-James P