Weird MB model...ignition problem

[DieselGuy]

Hello,

An uncle of mine stopped in town and we got to talking about MBs. Told him my 300SD is running strong at 284,000 miles. Anyway, he said his MB has a problem. I'm not sure if the model and engine he tells me exists, but it's an 84 300E (w123) with a 2.3L 16V 4cyl engine. He said it was an experimental car before that particular engine was put in the 190E in 86.

Now the problem...The car starts up fine, never hesitates, but it dies suddenly. He brought it 3 times to a German repair shop. They replaced the fuel pump, fuel filter, ignition module/or coil($450). He mentioned some relay the makes contact when the car is started but disengages right after.

Any input from the knowleable experts on this site would be appreaciated. Thanks in advance!

Nolan