Was driving my '80 model in Jan. when the engine began shutting off by itself. Finally found the time to tinker some more. Charged the battery and fired right up. Ran for a few minutes then shut off. Let sit(cool off) while I located and removed the fuel pump cover. With volt meter on fuel pump, started engine, watched 13.5 volts drop to 12.8 when engine shut off on its own.
It appears the fuel pump relay is not the problem.
Won't restart. Disconnected the cap at front of fuel rail, added hose, cranked engine over and watched fuel pour out of hose.
It appears the fuel pump is not the problem.
Put cap on fuel rail & cover on fuel pump(cool off). With ignition "on" the volt reading across + & - of coil is 2.8 volts. Start engine and the reading drops to 1.5 volts and drops more when reving engine. After a few minutes, engine shut off on it's own with 2.8 V still reading from the coil. Thought there should be 12V at coil then remembered reading about variable coil voltage on a Datsun 260Z and assumed since the engine was running with this low of voltage that the coil was OK. Starting to suspect the signal to the injectors(would that be a computer) or a relay to power the computer for the injectors. Do my previous checks and conclusions seem sound? Can you shed any light?