1989 W124, M103 won't start
 

PO replaced one fuel pump, drove it home, never got it started again. Spark looked weak, replaced cap, rotor, wires, plugs, still no start. Replaced coil, fired up instantly. Ran 4 minutes, shut off and would not restart... a few punky vacuum lines here and there, over 140psi fuel pressure if regulator is disconnected (the only way I can install my gauge). Measured 12v at fuel pump during prime, about 9 while cranking (old battery). It's run a total of a half an hour, but something is still very intermittent. CPS measured about 650 ohms. No blown fuses, reflowed all solder connections in FPR, OVP Relay, and some accessory relay behind the fuel pump relay. Car has about 200k on it, in very good shape thanks to Arizona's lack of the need for road salt...

Was the coil wire replaced?

yep
 

the entire HT portion of the ignition was replaced... unknown age and condition, so I just shotgunned it.

And yet, the question remains: Is there spark at the plugs?

CPS 650 ohms reading is to low it must be 800 ohms to 1100 ohms