92 740 B230FT turbowagon stalling problem....

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.

Mike

 

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:
http://www.swedishbricks.net/700900... Body and Throttle Position Switch Adjustment

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 ...

Pete (fP)