I have an 82 240 (k-jet)(with white dist cap)(M46 O.D) with 355K on the clock, that almost starts, it has the symptoms of a f/p relay where it sounds like it wants to start, but isn't getting enough gas.
This problem was a sudden onset, with no apparent warning(s)

I checked the in tank pump and the connector hose, I can hear both pumps running, and when I remove the out bound fitting from the fuel filter, it spews a steady stream.
I replaced the f/p relay with a known good, there is no joy. checked the plugs and replaced the wires, looked at the dist cap, rotor.
I am thinking there is a wire come loose from somewhere i can't see or am not currently familiar with. The wiring around the starter is somewhat frightening, and has been surgically altered to compensate for a combination of the previous owner's "adaptations" (like his welding the trans cross member to the frame) and the mother of invention, my son drives the car, and is out of the house to school, and then work from 0430 til 2000 five days a week, bout 110 miles a day.
So now he has my car(86 240 M46 OD).
If someone could direct me to a decent wiring diagram, I can forage for information with some idea of what i'm talking about.
I have been looking in the FAQ's and archives but haven't narrowed the search down enough to do me any real good so far.
Your assistance is as always greatly appreciated.
Paul