The RPM sensor was the first thing I replaced. It didn't fix the stalling problem or the occasional twitching tach.

An update though:

Two days ago, the car began hesitating, but would still idle fine (before it wouldn't even idle when it was having an "episode"). The poor running, but good idle is of course a classic sign of an AMM problem. So I bound out of the car with a hearty, "Ah ha!" -- as my passengers look on, disapprovingly, in amazement.

So I unplug the AMM, and plug it back in. The car immediatle runs fine, but a diagnostic code has been tripped: 1-2-1/AMM. Tripping a diagnostic code is new -- it had not done that earlier. I reset the code, and all is fine.

My question is, "Is the AMM a new problem... or could this have been the problem all along?" If the AMM was the problem all along, why was it not tripping any fault codes?

Any input is appreciated.

Jeff Pierce
--
'93 945 Turbo (201K miles), '93 945 (140K miles/I maintain for a family member), '93 945 Turbo (sold w 145K miles), '92 Mercedes 190E (174K miles), '85 Jeep CJ-7 w/ Fisher plow (225K miles), '53 Willys Overland w/ Fisher plow (sold to a loving home)