1999 ranger won't idle down when shifting at 3 grand, if run it up to 3.4 g ,rpm's will drop and all but stop at 3 grand . 2.5 grand drops closer to normal. Sat at red light in neutral , rev to 3 grand and it just stayed at 3 grd for at least 10 , clutch disengaged. No trouble code. help before clutch wares out!

 

Similar problem with my '97 auto 3L. High idle speed after warmed up, wouldn't idle down to less than 1500RPM in gear, ~2500 in N. Hard on brakes and trans! No codes set or pending. Found that cleaning the connections at the cruise control servo SEEMS to have corrected the problem. Still waiting to see if problem returns.

 

Welcome to FTE.

Maybe sticking throttle cable or plate, or maybe an acting out IAC. Does idle speed also act out anytime, like high or low idle speed???? If so, suspect the IAC, so try removing & cleaning it with a plastic safe sprey cleaner & see how it goes. Same with the throttle cable or throttle plate & bore.

Let us know what you find.

 

I pulled IAC valve cleaned it with maf cleaner and it idles at 1400 rpm but when shifting it dose idle down from 3grd . disconnected connecter on IAC and Idle is now at 900rpm. Going to reconnect IAC and drive it 10 miles and see if it is the PCM that needs to relearn , and if that dosn't work will pull IAC back off and have somebody turn key in ignition and see if IAC Valve plunger moves. If not will purchase new IAC. Thanks for the help ! Gary

 

Pull the battery B- cable to wipe the KAM, then perform the basic idle relearn strategy posted here. Ford Truck Enthusiasts Forums - View Single Post - high idle problem & let us know how it goes.

With the rpm where you said it was, 900 rpm, when the IAC was disconnected, had the idle screw been messed with, or do you have a vacuum leak somewhere, like a bad vacuum line, or maybe a faulty stuck open PCV valve, or hose or fitting to it or the throttle plate sticking open????

 

I check pvc and it check out ok. got a vacumm gage and put it inline , thought I had a leak some were too ,it check out ok, should read for colorado elavation 16hg and was at 16 1/2 hg .Took IAC valve off ,unpluged it and then turned key on, went back and replug it in and nothing moved ! so that should hopefully be the problem, order part $45.95 + sh Latter Gary Idle screw fine Thanks

 

Sorry about the long time it took to reply. Put in new IAC and Rpms do drop when shifting now but not as fast as I think it should, but rpm's dosen't sit at 3000 rpm. Still won't Idle down below 1400 .Maybe I need to figure out how to do a correct reset .Latter gary

 

Did you disconnect the battery to allow the ECM to learn the new IAC valve? Also, I would encourage you to check/clean the throttle plate and body with plastic safe cleaner. When I did mine (2.3 Lima engine), that cleared up a number of idle speed issues.

 

Did a 15 minute reset after I installed IAC and cleaned MAF sensor, throttle body and butter fly. Read other owners had problems with Idle after cleaning Maf sensor with proper cleaning solution . Going to unhook neg cable and try again.Idle screw never touch.