Help high idle above 20 mph with a manual

[brent98248]

Hi I've got a weird problem going on with my ranger. I'll start off with the fact that it's a 89 2.9 v6 5speed stx 4x4. I've replaced the idle air control valve and tps plus resetting the timing according to ford's specs. The problem I'm having is it will idle and drive just fine but if I'm going over roughly 20mph when I push in the clutch it will rev to 3500-4000 rpms without touching the gas and continue to do it through all gears until I'm back below 20mph. Any ideas?

 

[bcschief]

Test the clutch switch and make sure it's operating correctly, the pcm needs to know when you push the clutch down.

 

[brent98248]

Ok ill take a look just is weird that it does it over 20 mph

 

[gaz]

@brent98248 ,
My first thought is vacuum leak but I would take a hard look at the throttle cable (also look at the butterfly valve in your throttle body) see if it is getting hung up on something. "I wouldn't drive it" like that until it was sorted out.

 

[brent98248]

I checked both of those and everything seemed to be fine it will idle and rev just fine at speeds below 20 or just sitting in the driveway it also feels like it's down on power

 

[brent98248]

I will try to get a video tomorrow of it doing it

 

[rusty ol ranger]

You tried pulling the codes?

 

[brent98248]

Yes there are no codes

 

[rusty ol ranger]

I wonder if its something to do with the speed sensor on the trans. Should be on the tailshaft at the end of the cable.

Or transfer case since yours is 4wd. Itll be a little black box with a plug

 

[brent98248]

Ok so I was playing with it today and checking the things you guys told me to no avail I double checked the tps and got .97 at idle then took it for a drive witch is when I got the attached video when I got home it didn't drop to an idle even after I came to a complete stop so I unplugged the iac and it dropped to a idle. I took it for another drive and it didn't rev between gears and drove fairly normally so do I replace the iac again since it's the problem or at the very least has to do with it or what's your guys thoughts