Just got a 1991 Volvo 740 with 159k miles. Beautiful car. Absolutely perfect for my next ten years of driving. The prior owner used Volvo OEM parts on everything (even a new alternator) and the body is free of all the usual issues that come from an old Georgia car (faded paint, scrunched up door panels, dash cracks, etc.) It looks to be a Georgia Peach except for one small thing.

I can't keep it running...

So far I've done a TB cleaning, starter fluid, and the checking of all wires in the vicinity. What it will do is run for a couple minutes and then just conk out. I'll try to restart it and it will just cough/cough for minutes on end. I know it's not a California car. So I don't think the fuel pump relay would be an issue.

The mechanics told me that it had been running for about 30 to 45 minutes straight without a hitch beforehand. I'm thinking it may be a crank sensor, or maybe it's just getting too much gas and conking out? I was planning on putting a tranny from a non-turbo 1994 Volvo 940 into it (better fuel economy) but I wanted to get this engine problem licked first.

Any ideas... especially if they're good ones, would be most appreciated.