I agree. Check the coolant temp sensor. It is located in the thermostat housing

"IF" the Idle Control Valve is bad here is a quick fix that is supose to be temporary that I've been running for years.

Drill approx 1/8" hole in a "PENNY" and place it in the vacum line before the Idle Control Valve.

DO NOT DO THIS!


Zoomy, thats a BAD idea. Essentially you will be sealing the vent from the valve cover. This is bad because you will closing off the only means for the engine to vent out all the crankcase vapors. What will happen is that pressures will build up, and you can blow a rear main seal. I've seen it before. Also, Drilling a hole in there will not fix the problem. It will actually make it worse. Most Idle control valves can be restored to normal operation simply by cleaning them out.

I totaly agree with Jared on this, I too have seen before.
Remove the ICV And clean it with carb spray, make sure its dry before you put back on.

Jared --
Where is your article re: changing the coolant temp. sensing unit? My '89 iX has the same symptoms, and I'd like to take a crack at fixing it.

Thanks in advance.
JP

Send me your email address and I will send you all the articles on diagnosing idle problems.

Jared,

My vacum line from the valve cover is not plumbed thru/with the ICV lines.

But a seperate independent line. So to me this would not be a problem.

I have cleaned the ICV with carb cleaner to no avail.

You might want to look at the throttle switch under the throttle body. It may be out of adjustment.

10 years ago when I did this,
I poured thru my Bemtly manual checking every thing.

And it did turn out to be a bad ICV.

And One Penny is a lot cheaper than a new ICV.

While it may have worked for you, Zoomy, I have to stress to our other posters that this is something you do not want to do. You WILL eventually damage something.

I agree that this will "Only" work on the Early 'eta' M20.

The 'i' M20's are plumber completely different.

Unfornunately, I think in an eta mind set since that is what I own.

I can almost assure you that you will have a nice layer of water condensation inside your valve cover if you do this.

Sorry, I don't.

No sign of water/condensation when I pull the valve cover to adjust the valves.

then you must be the exception to the rule. Let me again stress to our posters NOT to do this. You will increase crankcase pressure, cause water condensation inside the motor and possibly blow the main seals. I learned this by experience. I'm trying to keep others from doing the same.