1994 F350 WILL NOT START

not sure on the model but some diesel have a high and low pressure fuel pump, once could be bad. low pressure push fuel from the tank to the high pressure, the high pressure pushing the fuel into the engine. or a rubber fuel line is bad letting are into the fuel system. look for heavy cracked rubber hoses

Fuel filter

those year trucks have bad lift pumps on the diesel engine. it is located near the fuel filter. they are also known for starving the injecter pump for lubrication oil due to the pumps low capacity. it is now recomended that an in the tank pump change over kit be installed

The P,T pump is likely the problem . The pump is inside the engine and is really expensive to replace.

sounds like a fuel pump has gone bad on you. turn your key but dont try to start. Have someone liste by your fuel tank and see if they hear a humming sound. If they do then your pump is ok. you can change your fuel filter at this point because it may be clogged.

SOUND LIKE THE ELECTRIC LOW PRESSURE FUEL PUMP CHECK FUSE TO SEE IF PUMP GETTING POWER. IF NOT REPLACE FUSE AND CHECK THE WIRE TO PUMP.IF PUMP IS GETTING POWER..REPLACE FUEL FILTER FIRST.IF IT DONT HELP.COULD BE THE ELECTRIC LOW PRESSURE PUMP. FAULTY. IT PUMPS DIESEL FUEL IT INTO INJECTION PUMP TO BE PRESSURIZED TIMED AND INJECT.SEE IF LOW PRESSURE PUMP DONT WORK THE WHOLE ENGINE WONT RUN.THE INJECTION PUMP NEED FUEL FROM LOW PRESSURE ELECTRIC PUMP TO RUN ENGINE.

If you have a schrade valve on the fuel rail, you can turn the key on and carefully depress the valve to bleed most of the air out of the system (valve is inside an aluminum or plastic cap similar to those found on your air conditioning system) You don't have a carb on there you have a throttle body...you can spray carb cleaner (not either) into it while cranking and it may help.
Sometimes though, a marginal fuel pump will give up when run dry of fuel. If pump cannot be heard with key on, check fuse and relay...if good, pump may have expired. also, make sure filter is able to flow fuel before replacing pump.

better check fuel pres and volume, id bet fuel filter or pump

I have a feeling you got a wholed of unleaded fuel or bad fuel
I drive a diesel box truck the station I always took it to the fuelman put unleaded in the diesal tanks and the truck just died it had to have the gas tank completed drained and cleaned out but also ask yourself how many miles are on it and when was last tune up and if you live in a cold climate I recommend a heater block plug

HAd the same problem turned out to be the fuel tank selector vlv not sealing off m/t tank on return line so when truck sat cold fuel would drain off injectors making me reprime injectors (airbound)
found this by dumb luck I got a hole punched in front tank (muddin )so I removed it and ran off back tank I observed fuel draining out unhooked return line next morning
replaced valve (and tank) problem went away
Disected old vlv (broken O-Ring)

by the way quick way to ck glow plugs ,What's your voltmeter on your dash doing when wait to start just goes out -If it's bouncing There workin