reving high when depressing clutch...

[Ranger_Rickster]

I have a 1998 3.0 manual transmission here to doing exactly the same thing. 2,900 to 3,000 rpm in between shifts or coasting with the clutch in all the way depressed until my truck comes to a complete stop. It is very annoying coming up to stop lights with a racing revving engine.

Mine seems to do it more now in winter on more humid or foggy days and very cold days.

I tried a brand new IAC valve right away and it was good for 2 weeks and then started coming back.

mine always idles at 1,500 to 1,700 first start up on cold days, and when warm idles at 1,000 i tried to lower it before by adjusting the idle screw to 700 or 800 and it did not like that, started stuttering.

I will do the battery reset tomorrow first, i did not do that when i replaced the IAC.
Then i will check for vacuum leaks with brake kleen.
Then check TB plate is clean or dirty.
Then check TPS voltage is good and smooth no spikes.
Check the wiring going to IAC, TPC, PCM, and the 2 coolant temp sensors for corrosion etc...

Thanks for all the advice in this thread, hope the OP has solved or is solving his truck.

I will report back if and what fixed mine here.

 

[Ranger_Rickster]

Well, i did a battery reset and my terminals were dirty started to get white build up. wire brushed the posts and terminals and put some spray protectant on them.

All electrical wires and connectors looked good.

TB was dirty especially behind, sprayed that with TB safe cleaner. return spring was okay, lubed up with lithium grease spray.

did / could not check TPS sensor voltage the connector was weather pack sealed and i did not want to damage it back probing it. did have 5.01 volts ref though.

checked for vacuum leaks with engine running and sprayed all vac. hoses with brake kleen and found nothing.

test drove it and it ran perfect, never acted up once, it stayed around 1,500-1,700 in between every gear change and with coasting with clutch depressed.

Hopefully this did the trick. : )