So, I'm turning to the forums as a last resort...

My girlfriend has been daily driving our 770,000km 1993 240 wagon for the past four years. Recently, the car died while driving about 3km from home. The fuel gauge has never been 100% accurate, and a tap on the fuel tank sounded like it was empty. Added fuel with a jerry can and the car fired right up. A few days later, the exact same thing happened a couple hundred feet from the first incident. Once again, it fired up when fuel was added to the tank.

We thought we were having issues with a falsely reading fuel gauge, or that the car was not accepting much fuel and was running out. I checked all the vent lines, sending unit, main fuel pump, etc. found the main fuel pump quite rotten looking, so we took the car to work the next day with plans on replacing the fuel pump. After an hour drive, half a kilometre from work, the car died yet again. By now we were carrying a can of gas with us. Filled it up, no start. Would crank, fire, then die. Would not fire unless keyed off and on. Had it towed to work where I had a hoist I could use.

This is where the fun begins. Replaced main fuel pump, no start. Checked every relay I could find that had anything to do with fuel delivery or the injection system. Swapped out fuel pump relay with a known good one, no start. Replaced crank position sensor with new part, no start. I hooked up a noid light and found I had injector pulse while cranking, but as soon as the engine fired, I lost both spark and injector pulse. We had the car towed to a friend of ours who happens to run a Volvo repair shop. After spending 2.5hours on diag, he too was stumped. He swapped out the crank sensor, ignition computer, proper spark plugs, checked fuel pressure, checked timing, and came to the conclusion that the ring gear might be loose or had somehow moved, sending a false signal to the crank sensor. Given the intermittence of the issue prior to completely dying, I don't agree with this, but am not ruling it out.

We towed the car home to our shop. After replacing the ECU and ignition amplifier module with known good parts, the car still would not start. Cleaned and applied dielectric grease to every spade connector and ground I could find underhood with no luck. An inspection of the main wiring harness at most bends has not found any obvious damage. I have power across the fuel injection fuse, #6 I believe, while cranking.

I'm not terribly good with old fuel injection, and this car has got me absolutely stumped. I'm hoping someone here may be able to offer a suggestion or some tests I could carry out to find the issue. Any and all help is appreciated.