I have a 1987 240DL and can't get fuel to pump to the injectors with the key on. Both fuel pumps are good. I gave them both 12 volts and they work. I wasted money on a new fuel pump relay. I have opened the new and the old relays to check for bad solder connections or anything else that looks wrong, everything is good there. I checked all of the fuses(duh). I can jump the fuse connections to get the pumps working, but I don't think that is enough to get the whole system working, because the car still won't run. I have found some good wiring diagrams and have a good idea how the fuel delivery system works. It seems that the fuel pump relay isn't getting the signal from the electronic control unit.
I have not checked every inch of every wire to see if there is a short somewhere. I have not replaced the electronic control unit or the ignition control unit(module).
I was wondering if replacing one or both of these units would be my next step.
Or if I should check something else?

I might have left out some things that I have checked in the above paragraph.

Any advice is greatly appreciated and this site is amazing!!