Good Evening folks,
I drive a 2002 3L V6 Manual transmission ranger

Here's what I'm experiencing:

When I am driving around in 2-4th gear and pop it into neutral to come to a stop, my RPMs will either stick at 2500-3000 RPM and stay there until I either pump the accelerator a couple times or I turn the engine off and then back on again (when I am at a complete stop). The throttle body had a professional cleaning two months ago and still looks very clean. I tested my TPS with my multimeter tonight and it appeared to be working normally based on the videos an stuff I could read about it.

The most recent work done on the Ranger has been getting several vacuum leaks fixed in order to resolve a chronic lean bank 2 code (P0174). The mechanic also replaced my dump solenoid and several gaskets in this process chasing down this leak. Prior to that he replaced my MAF sensor because it "tested bad" back when he was originally trying to diagnose the vacuum leak issue. This RPM sticking issue didn't occur until after the most recent repair where he finally resolved the lean bank 2 code.

Do yall have any ideas what it could possibly be and what I might be able to test it with? I have a BlueDriver OBDII scanner.

Thanks,

 

Just to check if it's a mechanical or electronic issue warm up the engine, let it idle and unplug the 2 wire connector on IAC valve
Idle should drop to 500-600 RPMs, barely running, or engine may stall, that's OK to, it means no vacuum leaks

If idle stays high you still have vacuum leaks but also need to proceed with the test anyway

IAC Valve unplugged
Start engine and go for a drive, may have to use gas pedal when stopped to keep it running if no vacuum leaks, lol
Repeat whatever causes it to idle high when coming to a stop, normal driving

If it still sticks at higher RPMs then it a throttle plate or throttle cable issue, so mechanical

If it doesn't stick at higher RPMs then its a IAC Valve or computer issue, electronic

All the TPS is used for is to give the computer a "heads up" if accelerating or to shut off injectors while decelerating(in gear)
If TPS was removed from throttle plate shaft then re-installed it might be off-center a bit and holding the throttle plate open a bit, tapping the gas pedal frees it up and allows throttle to close all the way
And a sticky throttle cable can do the same, you can lube the cable, take it off the throttle linkage and hold its end up, spray lube in it and let it run down inside the sheath, moving the cable in and out
Also check the throttle linkage spring, make sure it tight and snaps the throttle closed
If you have cruise control disconnect its cable from throttle linkage for now, just to make sure its not holding throttle open

 

Hey Ron! Thanks so much for the guidance. You're a life saver here.

Fortunately, I didn't have to resort to any of these fixes as the problem seemingly fixed itself. I didn't experience the problem again and have not experienced the same issue for the last two weeks or so.

When I asked the mechanic shop what it could have been, they speculated that it could have been that when they cleaned the the throttle body in June, it may have knocked some crap loose that eventually got into the IAC and caused the issue until it cleared out. I'm paraphrasing but that's the jist of it.

If I experience the issue again I use the trouble shooting methods you recommended and report back.