I am basically submitting a life and death question for this 760T here. It's currently at a dealer's service dept., who asks an initial, very steep, $900 to change the engine harness (wires are stripped -- but not bare -- in places). They propose to start chasing the starting problem from there, but appear unable to figure out what is actually wrong. Of course, diagnostics are not very lucrative. (We went to the Volvo dealership only after another non-specialist mechanic was stumped.) However, based in the symptoms over the last couple of months, it appears to me that the problem may be far simpler:

The symptoms:
I have always, bar this one last time, been able to start the car (even in cold weather) after extensive "cranking;" sometimes this may take 10 minutes or so with 20 or so attempts (I hook up another battery to maintain the spark). It gradually appears to get more lively -- from quite dead via intermittent firing to finally running. Sometimes it will start running and abruptly die. Once running everything appears normal. Immediately after being driven, it starts quite easily. Then it's back to square one.

The solution?
Both fuel pumps appear to be running fine and one suspicion is that it may be the feeder line in the tank that bleeds back, after sitting, to cause the intermittent fuel problems. (?) Another thought is that it may be the fuel pump relay. Not quite sure if the symptoms are consistent with the latter. (I found good descriptions for how to check this elsewhere on this forum.)

Does anyone with master mechanic experience have other clues as to what may be wrong here?

Thanks,

Are Flagan