Cold Start RPMS soar to over 6000???

[billindelicato]

So anyone that lives in the greater wny area knows how cold its been lately...thus contributing to my problem...When its cold and i start the truck the engine races to well over 6000 rpm on occasion and stays there for quite a while. then makes its way down to 2000...then races back up again...then finally after a while of shutting it off...starting it back up again...several times it hovers around 2000 rpms then gradually goes down to normal. I checked the boot on the throttle cable and it looks brand new(as most of my engine does) no build up of any kind on the cable...i pulled the tps and removed a very small amount of build up and that didnt help. no cel...no unfamiliar smoke/steam from tailpipe...and is garage kept. i know many if not all cars/trucks run high when its cold but its a different story when it runs high...settles down...then starts to run high again!!! please someone help me save my big red machine!!!

[amigo-2k]

maybe the throttle body butterfly is carboned up and needs to be cleaned?

[billindelicato]

i thought that too but i cleaned it out with x66 when i cleaned the pintle of the tps

[Ramblin Fever]

I agree, something's up. Those rpm's are way too high for your typical cold start.

It's gotten as cold as -18F here in the last few months, my truck is the same year as yours, running 10w-30 oil and fires up at around 1,800-2k rpm's and very quickly settles to 1k rpm's where it'll stay for about 2-3 minutes, then drop to 800 or so.

Check to make sure you don't have an air leak, too; how's your fuel filter and EGR valve?

[billindelicato]

ff add egr were replaced last year...it starts just fine with just one turn of the key...it just revs like crazy...

[trooperbc]

time to get two of you to check it out this next time with the hood up and you checking everything out while your helper is at the key to kill it if it stays too high. physically check out the throttle, just in case.
then possibly check the thermo sensors --CTS coolant temperature sensor and MAT manifold air temperture sensor, would be my inclination.

//bc

[amigo-2k]

check to see the throttle cable isn't gummed up with rubber from the rubber dust boot that covers it.

Search a bit and you'll find some photos about it.

[amigo-2k]

http://www.automotiveforums.com/vbul...ighlight=cable

I'll put this in the new Rodeo FAQ's too.

[billindelicato]

as i stated in my intial post the cable and boot area are clean as if they were new...any other suggestions?

[Canucklehead]

Originally Posted by billindelicato

as i stated in my intial post the cable and boot area are clean as if they were new...any other suggestions?

Could be the power steering pressure switch. It causes the engine to "idle up" when a load is placed on the power steering system, while it's not uncommon for them to stick when it's cold, I'm not sure that it would raise RPM to 6 grand.

[davey_92_rodeo]

sounds to me like either the cable going to the throttle body or the butterfly in the carb

[J-Mech]

I don't think that the Idle air controll would let the engine rev that high. It just doesn't physically have that big of a hole in it. The fact that when it comes down to only 2K makes it sound like you have two problems. Id check for a vac leak. Start by pulling and plugging all major vac lines. (Brake booster, and vac tree's, Ect.) If you can get it to come down a little that would help you run a little longer for diagnoses. 6K is way too fast to let it run. I think that the guy who said to check the temp sensors is on the right track. But my Q here is that it is soo cold out that even if they failed it should not rev that high. DEFINETLY check that IAC motor to see if it is opening all the way, if it is you have to find out why. You may need a scan tool of some sort.