I have a 98 Ranger with a 3.0 engine and the throttle body is sticking. I have cleaned it several times to include taking it off of the engine to get to the back side. It stll seems to stick at around 1300 RPMs at idle. I can turn it by hand and the idle will drop to 900 rps at idle. Is there any way to take the unit apart to further clean it or should I just replace it?

 

Sounds more like the IAC. A high idle can be a vacuum leak, but since when turning it by hand the idle drops, I suspect the IAC (idle air control valve).

It's the metallic cylinder on the side of the throttle body, you can remove it (two bolts, careful with the gasket) and clean it with throttle body cleaner, spray liberally until the dripping stuff is clear, then let air dry before replacing.

It's more of a band-aid, the problem will come back eventually, I remove and clean mine at every oil change while the oil is draining. Simple enough.

 

If you can manually close the throttle body, and the idle drops back to 900 RPMs, then the problem IS NOT the IAC, OR A VACUUM LEAK!!!! It could be simply a weak return spring on the throttle body. Make sure your throttle cable is free and not binding.

 

It's really very clear from your problem description, you don't have an IAC solenoid issue. Along with what Bob correctly noted, you should inspect the throttle linkage leading to the gas pedal (including pedal pivot) followed by a thorough inspection of the TB itself, in particular the operation of the butterfly when the cables are disconnected. Feel for binding, excess/unusual play (radially and longitudinally), etc etc.

 

you should check for binding cable but...
if you want to... take it off again and hold the TB up to the sunlight and see if any light bleeds through edges of the butterfly. then you will know if it's closing all the way or not...

 

Ummmm, there had better be some light showing through there; this is because there is an adjustment on the TB providing for default idle in the event that the ECM and/or it's components don't provide for proper idle control. No light showing = no default idle = someone tampered with it and it needs to be restored (easy to fix).

 

could be someone did try to mess wiith the stop screw. but if the butterfly doesn't close with the TB off the engine (ie lights shows through) then there is an air leak in the TB..and it will never idle right. also need to check as you say the side to side tolerences of the butterfly.

another easy test is to unplug the IAC .. what should happen is the engine will default to limp mode idle (ie lower idle). if this doesn't happen there is a vac leak somewhere.

also....before i forget (my new mantra for high idle) check the PCV valve!

 

Well...since ya'll are obviously so sure, let's give it a try.

Unplug the IAC and see what happens (do it with the vehicle warmed up...or it may die).

 

That is incorrect, disabling the IAC solenoid in itself does not validate/confirm a vac leak. Vac leaks are found the good old fashioned way, by inspecting. That is, unless there is today a new magical method that I haven't noted in the last 30 years and no F/T tech has mentioned to me................

 

well all i can go on is recent experience. the computer threw a code pointing to the IAC. it was a false code. the computer was fooled to think the IAC was bad due to a vac leak caused by a bad PCV valve which will in itself not throw a code. so in the end disconnecting the IAC would not make the idle default to around 750 rpms like it should because the vac leak was still present. the IAC was good and tested good electrically.

what i'm trying to say all was not as it appeared to be....

i'm not opposed (far from it) to tried and proven ways of testing for vac leaks. i don't think that's old fashioned at all , lol!
i think the OP should go ahead and see if the IAC is good and test for vac leaks especially the PCV.

sometimes, as we've seen, people tend to replace parts that don't need replacing and then will never know the real cause of the problem.

one guy recently replaced the whole manifold, the TB,TPS & the IAC when the high idle problem could have been solved with a simple $3.50 pcv valve...

ahh for the good old days when the idle was set by us not some stupid computer...