[bazar01]

I had a friend with an 85 240 DL and is doing the same thing. Sometimes no start and sometimes it starts. It stalled in the highway and had to be towed home.
I had the chance to troubleshoot the problem. Checked the outside fuel pump, it was running and we were getting fuel. Checked the fuel pressure regulator return and there was no fuel returning to the tank. So we replaced it, still no start.
Bought a Haynes manual and went through the ignition checks. Distributor has an ignition pick up coil. It has three wires. When you jump two wire terminals with ignition ON according to the manual, you should get a spark. We were getting spark but the spark was erratic and sometimes a continuous spark. Really strange. So we figured the pick up coil was bad. Bought the distributor ignition pick up coil and it was a pain to replace.
Did the ignition check once again and we got consistent spark.
Started it up and it fired up.Cars this old will have multiple issues. Troubleshoot systematically and patiently and you will get rewarded.
Good luck.