My 90 740T won't start.

On my way to work, the car stalled, no power, for about 1 to 2 secs. Then came back suddenly and the rest of the trip was fine.

After work, the car wouldn't start. It cranked and cranked and tried to catch, but wouldn't run. I started to pump the gas pedal and began to smell fuel. But no action. I thought, "no spark".

Towed the baby home. Read FAQs forever and I've deduced the following:

-I've got spark at plug cables
-I've got spark at coil

-the "pre-fuel pump" runs with key on (the main pump only runs after the engine engages, right?)
-I hear all the usual relays. Yes, well it doesn't "sound" any differant than normal
-the pressure regulator does not spray fuel through vacuum hose, that suggests that regulator may be fine.

-the engine cranks fine but won't engage
-I tried to overpressurize the fuel system (by turning on the pre-fuel pump) by turning on the ignition a dozen times before attemting to start engine and it seemed to help, in that the motor nearly caught, but that was all.

WEIRD PART

-I removed the fuel cap
-cranked the engine, and it came alive, then ran horribly while I pumped the gas peddle to keep it going
-It died. Cranked and it wouldn't engage again

The fuel cap is less than 4 months old. NAPA part tho', and the car has run perfectly for the last 18 months (since I've owned it). Lost gas cap 4 months ago.

So I have a fuel problem.

Is it the pre-pump or the main pump?
Is it the main pump relay? Pre-pump relay seems fine, since it works.
Is it the pressure regulator?
Is it the ECU (god, no) with a faulty pump relay circuit thingamabob?
Is the cap wrong? Haven't had any problems for 3 months and 29 days with new cap.

This came out of nowhere. No warning, so I'm thinking a part that just suddenly went. Sounds electrical, doesn't it. Where do I start?

Thanks you guys.











--
Mike in California '90 740 Turbo Wagon - Hydrogeology Field Vehicle