Hey guys, I'm at a loss on this one and am hoping someone can help me? Car is a 1990 240dl with lh2.4 and automoatic transmission

Shortish backstory, about a month ago coming back from the beach we're driving down the highway about an hour and a half into a 5 hour drive when out of no where the car starts surging like it's running out of gas - it has 3/4 tank at that time - before it eventually dies. I pull over and try to restart it but nothing. Engine tries to crank but it won't turn over. Unplug the amm doesn't do anything. We wait about an hour for AAA when for shits I tried it one last time and it fires. It runs and drives like nothing happened for about another hour and a half before it does the surging thing again and eventually dies. Same story again, we wait a while and then the car starts like nothing is wrong.

When we got home I replaced the fuel pressure regulator, o2 sensor, amm with a known good unit, and the intake tube with the throttle body gasket as there was a split in the accordian portion of the tube. This does not fix the problem. Hour and a half into my fiancee driving from Atlanta to Burlington NC it strands her on the side of I-85.

We got it home and I replaced the intake and main pump along with the fuel pump relay. I though I had fixed the problem, though when it is cold going up the hill out of my subdivision it would do the stall thing but not totally die and this would go away once the car was warm.

Then today, I'm driving home and it starts to stumble then stalls out and will not restart. I spent about 4 hours today trying to trouble shoot it and I still can not get it to restart and am at a loss as to where to look now. It doesn't throw any codes from #2 or #6 on the obd blinky light. I unplugged the amm and tried it, nothing. Unplugged the o2 sensor and tried it, nothing. I pulled a spark plug and rested it against the shock tower so I could see it while cranking and it is getting spark. I jumpered the #4 and #6 fuses for the fuel pump and tried it but still nothing. Plugs, wires, cap, and rotor are all new as of this past spring.

Only left with the ignition coil itself, powerstage or crank position sensor? They're all of unknown age. I get spark when I pull a plug so I'm left thinking the power stage and coil are still okay?