Volvo: Just cant figure it out!, volvo 240 dl, fuel pressure regulator

Question
Jimmy--
I love my 1987 Volvo 240 DL, but lately I haven't been able to figure out what is causing the intermittent rough idle/stall.  About six months ago I replaced the fuel pressure regulator and both fuel pumps (along with filter) thinking that I was getting a fuel delivery problem.  Now due to the fact that it usually happens suddenly and when it does, it just cuts out, I think it's electrical.  I know that it's not the Hall sensor, since I tried an alternate distributor.  I know that it isn't a computer problem since I've swapped both ECU and ICU with working models.  It might be something to do with the trigger from the ignition coil, since my shift light is always on, but I don't know if a bad coil would cause these symptoms.  What do you think?  Have you seen anything like this before?  Any help you could give me would be greatly appreciated.  Thanks!
Paul

Answer
Hello Paul! A bad coil could cause those symptoms. But I would also check the main engine wiring harness. This is the one that comes off of the ECM. They have been known to have problems. Also check the fuel pump relay. I hope this helps you.

Jimmy