hmm.. it's hard to say much from your description,

but that is exactly what happened on my '88 245 when the Air

Mass Meter died. There is a procedure for testing the AMM,

although it won't tell you much.

the best thing to do as a diagnosis for the AMM is:

when it won't start try unplugging the AMM, and

then starting again.. if it then starts (will sound

awful, though) you may have a shot AMM.

It is located, by the way, on the conduit leaving the Air Box next

to the radiator. it's either black plastic or metal, and it will

have a large electrical connector.

hope this helps..

it's a $500 part, but I was able to get one out of a wreck at

the junkyard for < $10.

also: if it is the AMM, it might have been your Air Box Thermostat

that cooked it. either replace or disable it in any case, as a

bad one will fry the AMM in no time. it's the little thermo-active

cylinder inside the Air Box that moves the preheater flap doo-hicky.