Okay,
90 Westy Syncro....
I've noticed that when the A/C comes on while before the engine warms up..
before the thermostat opens... the engine will stumble or stall... this does
not happen when the engine is warm... it seems that the colder the air
temp/engine in the morning, the worse it happens...

Took Digitool readings...
The only strange thing I could notice is this:

At cold idle the AFM reads 1.55... okay
When A/C compressor turns on radiator fan then AFM goes to 1.75- 1.80 and
the rpm DROPS to 800 or 850...

But at warm idle the AFM goes to 1.75- 1.80 and the rpm Rises to 1100 when
the radiator fan comes on...

So... it seems to me the AFM is acting correctly anticipating a rise in rpm
which needs more air... but for some reason the rpm goes down instead of
up.... idle stabilizer valve???

Your thoughts???

Thanks,
Bill