Idle problem; bounce from 1500 to 2100, and back again. (resolved), Click this thread if you want to see some shear stupidity on my part.. Options

[SleekCelica]

This car just seriously hates me. My idle bounces from about 1500 RPM's to 2100 RPM's and then back again, over again, pretty rapidly. Also, there is a LOUD sucking sound from the intake manifold, and if you plug up the IAC hole, the sucking sound goes away and it calms down a bit. This car can be in gear, and actually just pull itself without me giving it gas, and i can shift all the way to forth without giving it gas.

This post has been edited by SleekCelica: Jul 19, 2010 - 9:30 AM

[hurley97]

check for vac leaks

[Chhaos]

The idle bouncing sounds like what my CRX used to do. Turned out it was only a blown head gasket. The being able to shift into fourth with no gas whatsoever seems strange though.

[rave2n]

Certainly sounds like a vacumn leak...


Where are you located in SC? - If your close to Greenville, I might be able to visit and take a gander.

[SleekCelica]

i'm in columbia, so it's a possibility. I think my IAC has something to do with it though. Or maybe it's just trying to compensate for the vacuum leak.

[Gtguy22]

Most likely a vaccume leak. Spray carb cleaner around the intake manifold to find the leak, the engine will idle down once hit with the cleaner. Have you messed with the vac hoses? If so could be a crossed vac line. Also could be a blown head gasket, bad intake manifold gasket, bad throttle body gasket, bad Idle air control valve, map sensor maybe?

[SleekCelica]

My thoughts on that. I have no gasket between the throttle body and intake manifold. Map sensor is okay, because when I unplugged it, there was a definite notice in the running of the car. And by that, I mean, it didn't run at all. If the head gasket was blown, there would probably be coolant in the oil, and there is none. And I don't like spraying anything flammable towards my engine when it's running, because the last time I did that, well, let's just say I don't have any more stickers in the engine bay, and that a lot of my vacuum lines melted a little.

[SleekCelica]

I just checked, and my IAC does indeed click when I have the key on and insert the connector to it.

[hurley97]

When you cover the IAC hole with the car running and the throttle plate closed it should stall out. If it stays running its getting air into the intake manifold from somewhere else... i.e. vac leak.

[SleekCelica]

That makes sense *hits self on forehead* thanks!

[Gtguy22]

Also Im almost positive there should be a gasket between the throttle body and intake manifold. I hear you on the whole spraying flammable things into a running engine..... ive done it too, but aside from hearing it, checking them all individually, or running a smoke test, thats one of the easier ways to do it. You can also take needle nose pliers and pinch hoses until you hear a difference.

This post has been edited by Gtguy22: Jul 12, 2010 - 1:51 PM

[rave2n]

Also Im almost positive there should be a gasket between the throttle body and intake manifold.

Metal gasket last time I did mine.

[SleekCelica]

So rave2n, do you wanna meet sometime? I was trying to set up a meet, but obviously that won't work until I get this thing fixed

[JuMPiiN]

Its a vacume leak man, Mine did that it took me about 30minutes to find the one that was doing it, found it and it idles perfect at 1100 from then on. Trace all your vacume lines.

[rave2n]

So rave2n, do you wanna meet sometime? I was trying to set up a meet, but obviously that won't work until I get this thing fixed

Sure, just got the front all fixed up, and a few other goodies in the mail. Should be ready in 2 weeks, saw 2 black cellies today on the way home...if i spot them agian, i'm going to attempt to recruit 6gc members =P

[SleekCelica]

So rave2n, do you wanna meet sometime? I was trying to set up a meet, but obviously that won't work until I get this thing fixed

Sure, just got the front all fixed up, and a few other goodies in the mail. Should be ready in 2 weeks, saw 2 black cellies today on the way home...if i spot them agian, i'm going to attempt to recruit 6gc members =P

Cool, we'll keep in touch, in the meantime, I go into hardcore vacuum leak checker mode!

[Stambo]

Got the same problem on my 2nd gen 3s though. But, def no vacuum leak. Hoping just a cleaning on the iac will help the idle.

If i'm not mistaken the gt uses the same iac as the 2nd gen 3s?

[SleekCelica]

But my IAC works

[SleekCelica]

Alright I'm stupid. When I took the iac out to clean it, some parts fell out that I put back together. I put it back wrong! I put the valve upside down. Took it back out, put it right, and problem solved!!!!!!!

[SleekCelica]

Because it was upside down, it was pulling in the full potential of air, as if the valve was all the way open, that's why it would pull through the gears.