Another Rough Idle thread

[markt51]

For the past few months, Whenever my car is in Park or Neutral; it idles consistently at 2k rpms. Weather its cold or warmed up already. As soon as i put it in drive, or reverse, the rpms go back down to 1k and stay right there(from what i understand, thats because a load has been put on it) until i put it back in park or neutral.

Obviously it is a vacuum leak(correct me if im wrong). I cleaned out the ICV really good not too long ago.

Can anyone point me towards the hoses to look at, and which intake manifold gaskets should i look at. I plan on replacing all the gaskets and vacuum hoses, for peace of mind and just general maintenance reasons, but want to make sure that is my problem.

Thanks in advance.

[markt51]

Oh and i would also like to mention that maybe 1 out of every 100 times i put it into neutral or park, it will idle at 1k rpms for about a minute before it jumps up to 2k rpms.

[e30TED]

take your icv off, if it doesn't sound like a baby rattle when you shake it, then I'd bet that's your issue; unless you're sure you have a vac leak. Have you sprayed any suspect areas down with brake cleaner or done a smoke test?

[markt51]

I haven't Sprayed anything down yet. Just checked the ICV a few minutes ago(yea at 4 in the morning :p), something moves up and down inside when i shake it, but i wouldn't say it sounds like a baby rattle, but i guess it does somewhat rattle. Any tips for an at home smoke test?

[markt51]

I just messed with the ICV a little. So turned the car on without the a/c running, was idling around 1600-1700, i unplugged the ICV and nothing really changed. But when i go to plug it back it, when its about halfway plugged in, like the contacts are barely touching, the rpms go way down, but then i finish plugging it in they go stay at 1700ish

[markt51]

Messed with it a bit more today while i was draining my oil. Previously i heard hissing from a vacuum leak. That was about 4 months ago. I dont really hear it anymore, but im still planning on changing all the hoses. So here is my update:

Today i discovered when the can is in position 2(all lights on dash on, fan running etc) the ICV makes a humming sound. Similar to when you hear transformers, or other big electrical equipment hum, its also vibrating a little when its humming. Again this is when the car is on in position 2, accessory mode, whatever you want to call it, but the engine isnt started yet.

Does that sound like a bad ICV? Oh and unplugging the electical plug from the ICV when the car is running doesnt really change the idle at all much.

[5Toes]

no that means ICV is good.

check your tps.. its sooo easy and takes about 3 minutes with a multimeter.

[markt51]

k ill try to do that tomorrow. Ive been needing a good excuse to by a multimeter :p