A few times recently, my 1990 740 GL with Rex-Regina has cranked, but with only a little, intermittent firing until it has sat for a half hour or so, then starts right up again. There doesn't seem to be any relationship to dampness or outside temp, just that the car is fully warmed up. I tried a known good spare fuel relay, swapping the AC and radio suppression relays, with no result. I can smell fuel after cranking, so I think the fuel side is running (the in tank pump its a lot harder to hear than the Bosch versions).

So, of course, I ordered a new Crank Position Sensor from FCP Groton and put it in yesterday. Then the same thing happened again. I haven't had a chance to get a helper when it is doing this so I can see if I have spark, but I'm guessing I don't.

Anybody experienced something like this and can point me toward something to look at first. I have two other Regina cars, so getting spares to swap in is not an issue. I know the square coils sometimes go and can be opened. Can anyone tel me what to look for in a bad coil?

Thanks, as always.
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Andy in St. Paul. '89 244 153K mi, '91 745 Regina 206K, '88 244 184K