Engine shut down

1984 928S
Driving after fixing MANY vacuum Leaks drove it for 6.5 miles from 35 to 75 mph, turned around for the run back to the shop it the gas and startd off then SHUT DOWN.
1. Fuel tank Full fresh gas
2. Had battery power
3. Would not restart
4. Went and got trailer with winch and came back to car about 20 min later.
5. Car started ran for about 2 min then died.
I have a NEW coil since the old one was laying around the shop when I first got the car. The NEW coil is MSD spare from the racecar..
I have HEARD that the Cats get hot and the car can shut down.
Where would you look?
Already on the ignition system but since it started in the field the coil is suspect.
Thank You

Does the fuel pump run for a moment after a start-up attempt? You should be able to hear it buzz for a couple of seconds after the ignition returns to the run position.

It is always helpful to check if there is spark when there is a no-start condition. There are many possible causes of a no-start, so find out if there is spark. Please let us know if the fuel pump run when the engine is cranking over.

Often the relays are the cause of problem. For your 928 model, the fuel pump and AFC (L-Jetronic) relays are needed for the engine to run. The fuel pump relay for the L-Jetronic cars is a special relay, you cannot substitute a "standard" relay in the socket. The relay can be bypassed by removing it and plugging in a jumper wire between the 30 and 87 position of the relay sockets. If the engine runs when these positions are hot wired, it proves the relay has failed.

Found (3) Problems
1. Coil was bad
2. Fuel Filter was the original from 1984
3. Fuel Pump was iffy
Got new filter and pump on way.
After changing the coil the car fired but dyed due to NO fuel so that was the tell tail for me.
Thanks for the help.