1988 928 starts and runs goodfor 20 seconds then lose cylinders on both banks comp. good shut off and restart does same thing
Sounds fuel related. We could start by making sure the fuel is present and the (is it twin carb or fuel injected) is behaving itself. I assume this happens when the car is cold?...and can point to a choke or heat-riser issue- twenty seconds..eh? Does it seem starved of fuel, or choked off with too much fuel? a sniff of the exhaust when this happens would let us know. 1988 still has twin carbs??
petek with 1988 928 fuel pressure 60-70lbs new regulator
Fuel injection then, obviously-...achem, I have no friggin' clue. Sorry for wasting your ions then-
How's the coil doing? sounding like an electrical difficulty if all is 'skippy' with the fuel circuit.