Cold start Engine is Reving itself.
 

So I went to go warm my car up today to leave for work, it started fine but once running my RPM was jumping from 2 to 3 without me touching the gas or anything. This does not happen as long as I have the clutch pushed in but as soon as I let go my RPM's jump up and down. I'm not getting any check engine light It is the coldest day of the year today where I live only 7 degrees outside, does anyone know what is making this happen?

It seems to me that it's just trying to warm up...but I also heard about someone's neutral safety switch causing this. My cold idle fluctuates as well, but my clutch doesn't affect it. Does it still do it once the car has warmed up and is idling at the normal level?

why can't people search ... people these days just wanna someone to spoon feed their sorry ass ...

If the answe to cliffjumpers question is yes, then you have the same problem my car had. And as he said, it's the neutral safety switch.

This is called an 'idle hunt'. It is usually in response to the ECU not knowing if you are in neutral or not, usually due to some sort of failure in the neutral switch circuit (unplugged, frozen, damaged, melted, etc...)

Pushing in the clutch returns it to a stable idle because that has a separate switch, and the ECU now knows what state it's in.


High idle when cold is normal, a super high idle is also normal when it's REALLY cold (somewhere below 0f)

Yea this will happen, this morning it was about 5f here and my idle when I first turned it on was about 4k for about 20 seconds or so before it started dropping.

I agree with those who've said neutral switch is the most likely cause.

I always feel like an ass when I go outside to start my car and its really cold out.. Today it was about 9F, I started the car and idle went up to about 3.5k rpm. Its so loud.. everyone at the apartment complex also starting/cleaning off their cars look at me like i'm a scumbag.. I cant wait till it warms up..

^Hahahaha

:rofl: I know the feeling, jk I live in FL. I used to live in NYC though so I can empathize with you.

:scared: Same thing happened to me. About 10 deg. out - Revs jumping from 1k to 4k for about 5 minutes ! :wallbash:

I did I could not find enough information please don't feel the need to help me cause I didn't ask you specifically...My idle is rough even when it's warm but if i push in the clutch it's perfect settles right down to where it needs to be. I'm taking it to the dealer tonight to see what the problem is I don't see any way of doing it myself. Appreciate everyone's help thank you

Let me google that for you

*facepalm*

Humanity has failed ... again/

if your idle shoots to 4k when you start on a cold day, to make it go away all you gotta do is tap the gas pedal, worked for me this morning

Same thing happens to me as well but it is normal. Just let it warm up for like 5-10 minutes first.

What's really cool though is that vacuum noise at the beginning + the high RPMs. I love listening to it now. It sounds like a jet engine starting!

that's one way to handle it :lol: Learn to love it

Its just a switch behind your clutch pedal, same thing happened to me about a year ago, took me 10 mins and if I remember correctly like 10 bucks at autozone to fix.

Hey guys, I hate to reopen this thread but I didn't want to start a new one. Quick question. I'm in LA and we've had a cold winter this year (40-50 degrees) which by any other standards isn't cold. My problem with my idle hunt when cold, started on a 55 degree morning and it has persisted throughout the winter. I figured it was a neutral safety switch, though I didn't have any CELS, and I figured it wasn't cold enough to need to rev like that to get warm. Now today it was around 70 and the sun was out and no idle hunt when cold. I was just wondering if the conditions (high 80's and 90's) throughout the year and those in which my engine was rebuilt would lend to the idle hunt in 50 degree weather? With no cel, or as far as I can tell, no vacuum leaks, I'm in a bit of a pickle about the issue. I've also noticed my 8 a little more hungry for gas as of late, though that could just be because I haven't tuned it properly yet. Any help, or the mandatory flaming about searching and all would be greatly appreciated. It's an '04 with bhr midpipe, coils and wires, revi intake and duct, sohn adapter, lightweight flywheel, and an hks hi power exhaust by the way. Thanks!

wonder how many of those 19.8k posts are like this one ^^^ i guess high post count gives you the right to call people sorry ass. your signature is self describing ty

want a cookie ?

ppl think younger gen these days are completely useless for a reason.

The directive to search has everything to do with more experienced members being tired of answering the same questions over and over and over and over and over and over again. New members can quite literally find the answer to every question they can muster by reading the stickies or searching, and they can do it faster than they can create a new thread. Redundant (and necro) threads do nothing but clutter the site. Everything you need to know is here. Do a modicum of work yourself.