It is once in a while stalling when dropping down to idle while driving. Sitting in driveway, you can take foot off accel. and it never stalls. Problem seems to have gone away for a while, but now is back. THink J. Sweet said something about an adjustment on throttle body for this...idle stop, or what? Where located? Idle speed doesn't seem slow at all, its about 700 on the dash tach. Should I take inlet off of throttle body and spray out wilth something like carb cleaner first?
I have tried telling wife just to take foot off of accellerator a little slower...but she want a better fix than this ;-)
I would sure start out with a cleaning of the throttle body and the Idle Air Control valve, if it has been a while. The turbo sends a whole bunch of crankcase mist through them. I concentrate especially on the idle passage in the bottom of the throttle body, the one that goes from the throat on each side of the butterfly to where the knurled idle knob is. Might as well buy a new can of cleaner to make sure you have enough for the job!
BTW - for cleaning out that idle passage I remove the knurled idle adjustment screw. I start by counting the turns as I screw it in to where it bottoms out, then reset it to the original position when I put it back in.
Sounds like maybe a sticky ide air control. This thing comes into play when the throttle butterfly shuts off (assuming the switch is working and adjusted correctly). It then opens up an airway and keeps the engine running at a set speed. Unless it opens immediately, there'll be enough time for the engine to stall. The IAC control seems correctly adjusted -- 700RPM is about right.
The IAC is about the size of a small spray can and sits under the inlet manifold (at least, on my '90 760). Two fattish hoses go into one end of the can, and an electric plug goes into the other. Pull the hoses and plug. Pull the can out of its rubber mount. Squirt in some penetrating oil, shake it around and pour it out. Repeat, if you feel like it. Do the same with ordinary rubbing alcohol. This will get rid of most oil-proof varnishes that may be in there. Reassemble everything.
Check the butterfly switch. It's on the rear side of the inlet manifold just beyond where the big rubber hose connects to the metal. You should hear it click as the butterfly fully closes, and click again as it opens. If you need to make adjustments, read up here first:
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Check your throttle cable, too. If there isn't enough play, the butterfly won't close and the IAC won't switch on.
And a squirt of carb cleaner in the manifuld probably wouldn't hurt ...
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