We recently purchased a 15 year old 240 DL for our son to use during summers between college. We picked it out of an established, local used car lot "as is" with about 150k on the clock. Good physical shape and it started right up once the dealer hooked up a portable battery. Took it for a ride and we bought it expecting to get a few low-cost years out of it.

Almost immediately, the battery died. This was traced by our local service station to a failed alternator. Not an uncommon problem for a car this old that's been sitting on a lot for a few months. We replaced it and all was well again. Now, however, we are having an intermittent starting problem. The engine turns over, but won't catch.

We've had it back to the service station a few times. The first visit, he replaced the fuel flow meter. It died again as soon as we picked it up. This was traced to an electrical short that was killing the fuel flow meter each time a new one was put in. That was repaired. It seemed ok and our son picked up the car and drove it to his summer job -- 30 minutes away. After work, at about 10PM, he came out to the car and had the same problem. Engine turns, but won't start. Eventually, he drained the battery trying to start it and we had to go down and pick him up with a tow truck following behind. This time, however, after sitting overnight at the service station, the car started right up the next morning. Our repair guy asked to keep it overnight to see if he could repeat the problem, but couldn't. Wouldn't you know it, though, that night our son had the exact same problem and we had to go down there and tow him back again!

My question is: what else could be causing this kind of intermittent starting problem? Will you please let me know your thoughts?

Thanks.