Wanted to see if anyone could help with my stalling problem on an '88
240...

Car starts fine, purrs like a kitten at idle, and runs very smoothly
at speed.  However, there's a slight hitch in getting to cruising
speed - between 1500-2100 RPM, it stalls repeatedly.  It only does it
when the engine is warm.  It doesn't appear to be an ignition problem,
since the tach needle only drops to about 1000 RPM before it picks up
again.  Sometimes, it won't pick up again until I press the pedal to
the floor.  Seems as if something is interrupting the fuel flow for a
second, or longer on some occasions.

I've replaced the fuel pump relay, cleaned all of the grounds, checked
the main fuel pump fuse in the engine compartment and cleaned the fuse
block inside the car. I've also cleaned the electrical connections on
the AMM, the knock sensor, the coil and pretty much any other
connections on the left side of the engine. The car also has a new
cap, rotor and coil. I've pulled the in-tank pump, cleaned the "sock"
and used some Techron injector cleaner recently. The O2 sensor is
about 2 years old.  I've changed the fuel filter, pulled the in-tank
pump and cleaned the "sock," cleaned all the fuel system grounds and
connections, and this past weekend swapped the AMM.  None of this has
helped at all, and the problem seems to be getting worse.

What's left to check?  What other signals govern the fuel flow?  Could
it be the hall sensor in the distributor?  And could someone tell me
what the heck a hall sensor does, exactly? :)

Thanks for any help...

Ed