Erratic Idle Speed When Cold

[colonelcobb]

Hi All, I'm new here and have spent awhile reading a lot of posts and cannot find one that directly relates to my question.

My 2000 Windstar (3.8) has an erratic idle speed when cold. The tach bounces between 400 rpm and 900 and sometimes dies, only when cold. Once warmed up, everything is fine.

Other than the actuall engine and transmission, I've replaced just about everything there is to replace.

Autozone said two codes show: Idle speed sensor (I replaced it) and bank one lean and bank two lean.

Any ideas?

[mark_gober]

Originally Posted by colonelcobb

Hi All, I'm new here and have spent awhile reading a lot of posts and cannot find one that directly relates to my question.

My 2000 Windstar (3.8) has an erratic idle speed when cold. The tach bounces between 400 rpm and 900 and sometimes dies, only when cold. Once warmed up, everything is fine.

Other than the actuall engine and transmission, I've replaced just about everything there is to replace.

Autozone said two codes show: Idle speed sensor (I replaced it) and bank one lean and bank two lean.

Any ideas?

Sounds like your Idle Air Controller is malfunctioning. It's very easy to replace. It sits right on top of your engine and it controls how much air your engine gets during idle. (Works similarly to an electric choke on older cars). As your engine warms up, it closes off. Basically, it's an electric valve that opens and closes to allow air into the intake. They are fairly common failure items on Windstars. You can clean them and that might fix it. Remove it and clean it with B12 or some other carb cleaner and either a brush or a dental pick. If that doesn't work, you can replace it. (I had to replace mine). If my memory serves me correctly, it was around $40-$50.

Hope that helps.

Mark

[mark_gober]

Check out this link for pertinent info.

http://leckemby.net/windstar/windstar02.html

[serge_saati]

The erratic idle speed when cold is often cause by a vacuum leak at intake. Caused usually by bad upper intake gaskets (port seals) that getting worse when cold or by bad isolator bolts. That cause lean codes too.

You can check more info there: http://leckemby.net/windstar/windstar01.html

You can confirm the problem with a smoke/dye test or starter fluid at intake.
If it's the problem, you need also to replace the valve covers cause the original have a hole close to the PCV grommet. And other parts suggested at the website.

[danielsatur]

I wonder if a cold smoke test would pic this problem out?

[serge_saati]

Not an exhaust smoke test, but an intake smoke test. If he sprays smoke at air intlet, he could see smoke escaping from intake manifold. With a dye and UV light it's even more obvious to find the leak.

Or by spraying propane at suspected leak point and doing an exhaust smoke test to see the increasement of hydrocarbon. It will be even higher at cold but it's not an accurate test.

[mark_gober]

A far more common problem on these Windstars is the IAC valve. Vacuum leaks will typically surge regardless of whether the engine is warm or cold. The IAC is particularly noticeable just after starting a cold engine.

[serge_saati]

Of course, but he says he raplaced the "Idle speed sensor". He would mean the IAC valve.

[colonelcobb]

Quote: "A Windstar without the check engine light is not a real Windstar." ROFLMAO! (I love that one!)

Thanks for all the great help guys!

[mark_gober]

Originally Posted by colonelcobb

Quote: "A Windstar without the check engine light is not a real Windstar." ROFLMAO! (I love that one!)

Thanks for all the great help guys!

ColonelCobb,

Did you get any headway on the problem? Had you replaced the IAC on your car? I missed it in your original posting. Is that what you meant when you said Idle Speed Sensor?

Mark

[colonelcobb]

Mark,
Thanks for your question. Yes, I replaced the IAC with one from a "dead" Windstar from a local junk yard. I had to clean and soak it in WD-40, but this one worked.
Idle improved, however, I now suspect an air-leak at the plenum that I will be addressing this weekend.

Thanks again

[mr joe o]

Had same issue on a 2003. Replaced the intake gaskets, but still had some issues. Found 2 small cracks on the coil. New coil fixed the issue.