Firstfives.org

I've been having this problem for quite some time now and can't seem to figure it out.

When cold started it will idle around 1200 rpm, then slowly climb to 2000, after about 30 seconds or so it will slowly fall back down to ABOUT 1500 rpm. But I can't seem to get it to go lower. I like it at about 900-1000.

Everything is clean. Went through the Throttle adjustments.
Cleaned all vacuum ports, used starter fluid to check for vacuum leaks. (should I use something else?)

Existing issues - Thermo bleed screw is stuck, so I can't bleed the system after in installing new radiator.

Notes;
At running temp the Air Flow Meter door is slightly opened, ABOUT 1/8" or so. Is this correct?

Idle Adjustment screw is set all the way clockwise, in an attempt to get the idle down. No luck.

New Aux Air Valve installed last year.

Accelerates perfectly through to 6000 rpm.

Other then the high idle it runs great.


Any help\ideas would be greatly appreciated.

Sorry 'bout your problem. If you bend over from the passenger side of the motor & look under the throttle body from the windshield looking forward with a flashlight, you'll see a hole with a slotted screw that's about 3/4 of an inch across. Don Daynes helped me adjust the idle using this adjustment.
Righty high, lefty lower idle. I really don't think the e12 is suppose to run with the AFM idler giswitchie all the way closed. You might want to find a happy medium between the two.
I use a screw driver that's about ten inches long. Don says he just leaves it resting in place. Which to me means that he doesn't drive hard anymore.
lemme know if this helps. Greg

About the 'thermo bleed screw'; saturate it with WD-40 daily for maybe three days in a row. Try it. if it doesn't work try it again (be patient) or use what some else says to use. Use vice grips, choke up on 'em and, never force anything. If you get to the point where you think you should stop; STOP. add more WD-40 or somethin' else. Try it later.
When you finally free it enough to remove, replace it with the updated version that has a metric head whatever size it is, maybe a 6mm. By now I know you have one from the dealer just waiting to be in place. I rarely recommend the stealer items, but, in this case, yeah.

Check timing and the retard side of the vacuum box on the distributor. Too much advance will cause a high idle. Also make sure the linkage is not binding and adjusted so things are closing fully. The aux air valve can cause a problem if it's sticking and letting too much air by. High fuel pressure can do it especially when cold. And don't forget about plain old vacuum leaks in those 30 year old hoses. Check all of them, including the ones going down to the AAV.

GripGreg

Are we talking about the same screw,..Throttle Bypass Screw?

That's the adjustment I was referring to being all the way clockwise\right, which is lower idle (?).

Is there another adjustment screw I am missing somewhere? I've had the car 11 years, never saw anything else.

Mike

What am I looking for on the on the retard side of the distrib? Am I checking vacuum there?

Is the door on the AFM suppose to be open about 1/8" at operating temp?

I'll have to look at the timing, currently I don't have timing light. I moved a few times and lost it. Suppose i ought to get one.

I sent this car to a Mech, because I didn't have a decent place to do it myself. Cost me $500 of work to pass emissions, and it still wouldn't pass. Took it back 3 times, never got it to pass. Then moved to an area that didn't test. Which raises large suspicions of timing, nor an ohm meter. I'm kinds stuck doing this cave man style at the moment.

Lets say the timing is correct for right now. Besides vacuum leaks (which I've been crawling all over that car looking for one). I cleaned all the electrical connections , of course not being able to get to the AAV yet. Are there any other ideas.

Another symptom I found today was when I closed the hood, the idle hesitated, like dipped quickly. While looking for a short and tapping to get the same reaction. I found that if I rapped on the Computer box (?) on the passenger fender wall, the car idle stuttered very briefly. Is there something wrong there?

I'm not that mechanicaly aware, seriously. But the other adjustment is underneath the AFM. I'm still learning from this website. Don't forget to plug in the connector to the AFM before you see if anything works.
Good Luck,,,,Greg

JonC wrote:Mike

What am I looking for on the on the retard side of the distrib? Am I checking vacuum there?

At idle, removing that vacuum hose should raise the idle speed. If it doesn't, it means the diaphram is probably leaking and not retarding it like it should.

Is the door on the AFM suppose to be open about 1/8" at operating temp?

Sounds about right.

I'll have to look at the timing, currently I don't have timing light. I moved a few times and lost it. Suppose i ought to get one.

I sent this car to a Mech, because I didn't have a decent place to do it myself. Cost me $500 of work to pass emissions, and it still wouldn't pass. Took it back 3 times, never got it to pass. Then moved to an area that didn't test. Which raises large suspicions of timing, nor an ohm meter. I'm kinds stuck doing this cave man style at the moment.

Hey, I bet that's how the factory did it the first time.

Lets say the timing is correct for right now. Besides vacuum leaks (which I've been crawling all over that car looking for one). I cleaned all the electrical connections , of course not being able to get to the AAV yet. Are there any other ideas.

Another symptom I found today was when I closed the hood, the idle hesitated, like dipped quickly. While looking for a short and tapping to get the same reaction. I found that if I rapped on the Computer box (?) on the passenger fender wall, the car idle stuttered very briefly. Is there something wrong there?

That could indicate a problem with the ignition control unit, but it still shouldn't affect timing.

The screw in the bottom of the AFM is the idle mixture adjustment. It bypasses "false air" meaning non metered air as a means of adjusting the CO at idle. Technically screwing it in might reduce idle some, but it's not an idle adjustment. Once it's warmed up it really doesn't affect things much, the O2 sensor input overrides it and corrects the mixture at idle and at speed. It can be a band aid to kind of correct for other problems, but it has very little affect on O2 sensor cars.