Yet another high idle problem

[Busted2000SE]

Hi Everyone,

I tired to search this forum for an answer but couldn't find one using the search.

Here is the deal:
2000 Focus SE DOHC manual trans. 80k on the miles.

The wife drives this car everyday. Within the last 12 months she complained about the engine not coming down to a normal idle sometimes. Sometimes it would hang at 1500, sometimes almost 3000. She tried wrapping the throttle thinking something was stuck, but never any luck. After some online reading I found quite a few people solving similar problems by changing the IAC valve, some people even said cleaning the carbon out of it fixed thier problem.

So I decided to take it off and clean it out. There was minimal carbon in the valve, but I did clean it up. I put it back on and it drove fine for me. Wife drove it another 3 weeks, ran perfect. Then one day all of a sudden it starting acting up. So this time I thought that something has to be wrong with the valve, weak spring, messed up seat, f'ed electronics in the thing. So I buy a new one and throw it on.

I drive it around a little bit and it seems fine. RPM's don't come down as quick as they used to but they came down to normal. Actually the car seems easier to drive when the R's don't drop off as fast. So I throw the wife the keys and she is back in business.

Fast forward 3-4 months to present day. She is coming home from the mall today and it starts doing the same thing. Now I don't know what the hell it is.

Can anybody help me???


Brian

[Sponsor]

[Busted2000SE]

Bump....

90 some views and no help?? Come on, someone has to have had this problem before.

[whynotthinkwhynot]

Well a new IAC fixed it for a few months. Did you get that part from a Ford dealer or is it a parts store part?

Are there any other problems with the vehicle that might point to something?

Have you taken it to a parts store and had the codes scanned? If you do that, then be sure to write down the code numbers that show up. We have more information on what each code means than they do, so bring those numbers back here and check them against our DTC list.

You should also clean the throttle body to be sure that there's no buildup in there that might be holding the throttle open.

[Busted2000SE]

I have a code scanner. It doesn't throw any codes. Throttle body is very clean. This engine doesn't have any carbon build up anywhere.

The replacment IAC is NOT a Ford IAC. Ford wanted $300+ for a new IAC. I got a Delphi one from the local parts store for $100.

[Busted2000SE]

I used some carb/throttle body cleaner and got some of the junk out from around the butterfly. Is the blade on the throttle body supposed to have a countour to it? this is the first one I had seen that wasn't flat.

[Busted2000SE]

Can anybody answer my throttle body question?

[BC_ZX3]

Originally Posted by Busted2000SE

Can anybody answer my throttle body question?

Yes, a stock throttle plate has a "ramp" on one side of the throttle shaft. Hard to describe. See the pics.

[Busted2000SE]

It looks like the throttle body is o-ring sealed to the manifold. Is it possible to remove the TB and be able to re install it with out a new gasket or o-ring.

[BC_ZX3]

Yes, if I understand your question correctly. The gasket is re-usable and need not be replaced every time you have the intake apart.

However, you need to ensure the gasket is serviceable before re-use or you will introduce the possibility of unmetered air entering into the intake manifold via gaps or breaks.

[Busted2000SE]

Ok,
Just an update and maybe some additional help. After 3 IAC valves from local parts stores not fixing the problem. I bit the bullet and bought one from the Ford dealer. Seemed to fix it. Now that it is summer time and the weather is hot, the high idle issue has come back. Still very intermentant.

I have a hard time thinking I have another bad IAC valve. If so, that is like 4 in the last 2 years.


What I was planning on changing is the TPS and possibly the PCV valve. Anybody think that is a bad idea?

I have also really ruled out a vacuum leak. As I understand vacuum leaks, it would be a constant issue, not whenever it feels like it.