High revs when idling, no one knows what's wrong

[Tytanis]

Mine did this as well. Check the PCV valve, run your hand down all the way to the bottom.

Another possibility is the idle control solenoid.

[Infernal01]

Originally Posted by Tytanis

Mine did this as well. Check the PCV valve, run your hand down all the way to the bottom.

Another possibility is the idle control solenoid.

Changed both, nothing happened.

[Tytanis]

Originally Posted by Infernal01

Changed both.

What about the PCV hose?

[Infernal01]

Originally Posted by Tytanis

What about the PCV hose?

If it's this one, then i've already changed it, the rest of the hoses didn't seem to have any problems:
http://imageshack.us/photo/my-images/844/imag0252rr.jpg

[Tytanis]

Originally Posted by Infernal01

If it's this one, then i've already changed it, the rest of the hoses didn't seem to have any problems:
http://imageshack.us/photo/my-images/844/imag0252rr.jpg

I would still get a smoke test done. My local shop charged me only $50 for it. This will help you ELIMINATE any vacuum leak suspicions.

A few other questions;

Does this only happen when the A/C is on? Maybe it could be the ECT sensor?

I still 90% believe it's a vacuum leak.

[Infernal01]

Originally Posted by Tytanis

I would still get a smoke test done. My local shop charged me only $50 for it. This will help you ELIMINATE any vacuum leak suspicions.

A few other questions;

Does this only happen when the A/C is on? Maybe it could be the ECT sensor?

I still 90% believe it's a vacuum leak.

Could you please tell me what a smoke test is ?

At every car service i went, they checked for leaks, they used some kind of special spray that would show if any air is leaking, i don't think 4 services could miss that. They checked and rechecked, everything seemed fine, plus, i doesn't behave like a leak, there's no fluctuation.

This happens if the AC is OFF, so i don't think it has anything to do with it.

[Tytanis]

Originally Posted by Infernal01

Could you please tell me what a smoke test is ?

At every car service i went, they checked for leaks, they used some kind of special spray that would show if any air is leaking, i don't think 4 services could miss that. They checked and rechecked, everything seemed fine, plus, i doesn't behave like a leak, there's no fluctuation.

This happens if the AC is OFF, so i don't think it has anything to do with it.

A smoke test is when they hook up a smoke machine (oil-based) at 2 PSI to your intake. Any leaks are then visible. They also use mirrors and glasses with a black light.

Using carb spray is risky and you won't be able to find leaks non-accessible.

[Tytanis]

Here's a great video showing how it's done:

http://www.youtube.com/watch?v=BkOSHc7JaKE

[mikebontoft]

its a better idea than just spraying Carb cleaner until the idle changes. I found a leak on car yesterday at the intake manifold (2.3 duratec) and It looks like the manifold warped or cracked because its plastic. smoke would have pointed it out faster but j
I don't have one here.

[Chris_HT]

Originally Posted by whynotthinkwhynot

You're wasting your time running a new cable from the alternator to the battery, as long as the battery is remaining charged (you'd know in a day) then it is working. Besides, high voltage will cause that problem, not low voltage.

I usually agree with all your posts, so don't take it as a bite for discussion, but I disagree....

and I tell you why,

In my understanding: computer will keep higher RPMs to keep up with increased electrical load - so, if there is a problem with cable charging the battery, or grounds, it's not getting enough 'juice', and the 'normal load' becomes 'high load' for the computer, and it ends up reving. Now why would A/C make any difference? well with A/C on the computer will keep higher RPMs to keep up with extra load that A/C compressor adds, which means alternator has a little higher output at that time too, which may be just enough of difference to keep computer satisfied with it's energy output.


And why would I said it all? Because I had problem with electric installation in my SPI, and it did weird things, almost like having an annoying ghost in your car who just likes to mess up with everything :P so ye, I experienced higher revs for a few seconds after coming to a full stop, and just taking care of the wiring fixed my problem.


Now I'm a noob, so feel free to point out why i'm wrong :D