Idle Problems

[bhyde]

Well,
I adjusted the idle switch and made sure the throttle was contacting the switch at idle (duh), it does. I also did the little procedure where you put the jumper between the B and C connectors to bypass the volumetric flow meter and then adjusted the idle using the screw on the side of the throttle body. With the bypass jumper in place, I can get the idle to 800rpms no problem, but as soon as I remove the jumper the idle goes back down to 500rpm. This would tend to rule out an ignition coil problem (I think) and point to a bad ICV or a vacuum leak. I'm leaning towards the ICV being the cause, but I've already taken it off and given it a good cleaning and verified it makes that "buzzing" sound.
I see from some of the other threads that the ICV, even though it seems to be working, may actually stick or not move freely enough to do the job. Guess I'll just add an ICV to my cart here at Pelican and see if a new one does the trick. I'll also get some starter fluid and see if I can find any vacuum leaks. I F'ing hate vacuum leaks.
Does any know if there is an access port on the intake manifold where I can measure manifold pressure with a vacuum guage?

[Porsche_monkey]

I had exactly the same problem with the idle speed adjustment last week. I kept going back and forth with and without the jumper and finally got it to idle at 700 rpm, but I am not convinced that I've done it right. Eventually I got to the point where I was just getting it to idle at close to 800 rpm without the jumper, so the whole procedure seemed useless to me.

Also, the link I posted says the timing should go from 2 deg ATDC to 12 deg BTDC as soon as the idle switch opens. My car does not do that, the time jumps back to about 0 deg as I move the throttle, and moves progressivley back as I rev the engine. There is no big jump. And, I would say that my car does not jump from 800 to 1,300 rpm as soon as the switch opens, which is also supposed to happen.

I am guessing the jumper should close off the idle air control bypass, so this sets the base idle speed, it can only go up from there. Maybe the IAC isn't shutting off completely when the DME controls it?

I am hoping someone can shed some light on this.

[DonMo]

The AFM on the 3.2's have a tendency to wear a space on the track and give strange readings sometimes. Remove the connector at idle and see what your car does. If your car's idle goes up or down, it means the AFM is sending a off normal signal to the brain. I have been told if your mixture is correct and your idle is set right along with a vaccum tight car with proper sensors, you can disconnect the AFM at idle and nothing changes.

[rallyracer]

smack your ICV with the plastic handle of a large screwdriver while idling. if it changes, replace it. these generally last 5 yrs/ 60k miles, give or take, and always act as you describe when they begin to fail. sometimes cleaning them helps for a few thousand miles, but mostly not. eventually, it will die when you come to a stop, and you'll start to learn a new use for heel and toe footwork! having the a/c on usually makes the problem worse. of course it could be something else, just not likely.
David