As mentioned in the other posts, if indeed the fuel system has lost prime the engine will have to be cranked for at 30 seconds multiple times. The accelerator pedal will also have to be floored while the cranking occurs. I would suggest having another diesel's battery (or two gasser batteries) connected in parallel (with 4 AWG jumper cables) with the 300TDT's battery while cranking to keep the charge up. Also don't exceed 30 seconds of cranking time to avoid burning out the starter. If the fuel system prime has been lost, the engine will run rough until the air is out of the system.

-Steve

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1987 300TDT smoke silver w/ burgundy leather interior
2000 VW Passat wagon indigo blue w/ beige leather interior
1985 Mustang SVO
1970 Chevrolet K10 fleetside, shortbed