well today when i went to school i went to shift and it held about 2k rpms for a long time before falling. well i tried cleaning the IAC but it is still doing it. if i rev it to 3 grand it holds steady at 3-3.5k in neutral with my foot off the pedal completely. when it revs up to 3+ i cant get it back down unless I engine brake. around 2k it will drop after about 5-8 secs. and 3k+ it holds steady till i do something. Any suggestions?

RPS/RF double post!! trying to get info quick i need to figure this out asap!

 

You sure nothing is holding the pedal down? My floor mat slipped up one day and it did the same thing.

 

no its not the matt my 04 4.0 5 spd does this too and idk what it is... im interested in finding out to

 

well i have checked the vinyl possibly getting in the way but i will check it over again tomorrow to completely rule it out. Over at RPS one guy is having problems but not similar enough to me and they said it was his IAC sensor. Are there any other sensors other then the IAC or Throttle position sensor that would cause any thing like this? well mine started today. I took off the throttle body yesterday to try and do a little work to get my 60mm to fit but i haven't ported the upper intake manifold or anything like that. nothing that i thought could cause this. i was working on it all day today cleaning the IAC and seeing if that would help but nothing. I stayed around the throttle body because thats is the only thing i have done to the truck recently.

 

Maybe the cable is getting hung up on something. I know that when I shift the revs are help up a bit on purpose but if I rev in neutral they drop back to idle. IDK man. Just trying to give you ideas.

 

Instead of trying to save a messed up IAC(which usually don't work for long), how about getting a new IAC valve? Cured all my RPM's staying issues.

 

yeah that is a possibility as well. And that could very well be the case!! i appreciate the ideas i need as many as i can get!!! gotta miss school to work on it tomorrow since its so damn hard to drive the thing. im sure all of the unnecessary revving is not good for the clutch either!!! haha. how much did the IAC cost ya? im low on funds and still looking for a job :(

 

Get that new IAC installed, then if that doesn't solve the problems, start looking at vacuum hoses.

 

my truck did the exact same thing. i replaced the IAC but i still didnt like the way it hung RPM's. i made a restrictor plate and that helped a bunch but i ended up just unplugging the iac all together and it runs way better now i think. it will throw a code but it works fine. i can rev it up and it goes right back down to idle immediately and when i shift it goes right down. try unplugging it and running like that for a wile. u will probably like it.

 

alright. ill do that for sure. just hope it doesn't cost a lot. ill have to spend it anyways if its the IAC but man do i need a job!!! lol i will def unplug the IAC to check the IAC that is def a good diagnostic check and possibly temp fix till i get that Christmas cash

 

Looks like 51.99 from Autozone.

 

alright well that's not to bad. ill unplug it first for diagnostic purposes then if that's the case then new IAC here i come! Thanks for all the ideas. we shall see tomorrow morning what the heck is going on with this thing!

 

ok IAC < is a what?

 

Idle Air Control valve.

 

ooooooooo

 

idk if ur truck is like mine the new iac wont do any thing....one day it will just decide that it wants to idle higher and hold rpms. the best thing for me was to unplug the iac and leave it like that.

 

i wonder if there might be a short somewhere in your wiring harness!! might have happened to mine to possibly?

 

It was the IAC thanks guys!! got it unplugged for now so i can run around town and do the things i have to do.. Its like driving a completely different truck. i think it was going out a long time ago. i know when i turned the ac on it would hold revs but not bad. so new IAC here i come!! damn sensor! lol