Hello All,

'91 940 Turbo was giving me regular trouble with starting. Car would crank strong, but not fire up. Changed coil, fuel filter, etc. to no avail. Changed distributor cap and rotor and problem when away...for a while. A few months ago, was driving around fine at fairly low speed, came to a stop, went to turn left, car sputtered and died. Few hours later, car started fine and ran home. Tried to restart again and no go. A couple of hours later, tried again and it started right up. After that, ran fine for several months. Note: I never had a spark detector handy when the car wouldn't start, only when it decided to behave. However, for what it is worth, I always heard the fuel pump running prior to (attempted) start up.

A couple of days ago, decided to replace the power stage, fuel pressure regulator, and ignition switch. No problems except that I couldn't find the button on the ignition lock to pull it out for easy access. Seemed to swap it out okay anyway. However it is a bit stiffer than I was expecting it to be.

Tried to crank car and no go. Tried a few more times, still no go. Rechecked the connections and gave the relatively new coil a rap, started right up. Drove around the neighborhood, without any problems. No sputtering or hesitation. Came home, shut it off, tried to restart, no go. That was three days ago, and the car hasn't started since.

Fuel pump is still priming prior to crank.
I have confirmed that there is no spark.
OBD has no recorded faults.
OBD test for RPM sensor gave odd result (LED stopped flashing, but no error code followed).
RPM sensor cable was noticeably deteriorated.
Replaced RPM sensor.
Replaced coil and spark plug wires.
Still no start.
OBD test for RPM sensor giving same result (LED goes out without giving a message).
Put the old Power Stage back in, to no effect.

Car still cranking strong.

Please help before I begin inventing new forms of profanity.

Thanks!

PS I'll make a $25 donation, in honor of the person who provides the answer to this problem.