89 Astro, everything stock V-6, automatic.
Van starts fine. Runs fine highway or city. As I'm decelerating, as if coming up to
a stop sign, the engine wants to stall WHEN I start touching the
brakes and ONLY when the outside temp is maybe 90 degrees or more.
It's as if the RPMs suddenly drop so low that the engine just quits.
Once in a while it will stall in a similar manner when it's just parked
and idling, no brakes or other loads applied. But always when the
outside temp is high.
Doesn't seem to matter what the engine temp is, just started up
or running for an hour, everything above is still the same.
Does seem to happen more often when the A/C compressor is on.
A/C fan doesn't seem to make a difference. But the A/C on or off
DOESN'T seem to make a difference if the outside air temp is
in the 80s (F) or lower.
New engine 30k miles ago. New battery that always tests
fine. New plugs-wires-distrib cap-rotor
just a couple months ago. Replaced a bunch of vacuum lines
(the small lines, not the big brake booster lines). Still can't sense
any vacuum leak. OBDI codes don't show a thing. I have the hell
grounded out of this van, battery, body panels, chassis, alternator,
exhaust etc. Batt voltage is always good, 13.8 or so, sometimes
even higher. No electrical loads, including brake application, cause
the batt voltage to drop more than a couple tenths and then it
typically comes right back up as the alternator "catches up" with
the load.
I seem to recall something about the brake switch doing something
with the onboard computer, telling it to keep the rpms up(?) or
something similar.
For some reason, I still want to suspect vacuum.
Where's the magic "push this and it'll be fixed" button?...
Lumpy
Even if I didn't like the look of
