1994 351 wont start
 

I just bought this truck tuesday. i looked over everything from top to bottom the truck is in ghreat shape and motor is clean. The guy i bought from said it sat longer than it was driven. I live 30 miles away i get 2 miles from house and everything just shuts down and check engine light came on coming home. When i was buying guy said alternator was going bad. I got that tested it was good and battery was good. I got a code reader and 114 116 121 and 542 codes are popping up i think the only continuous code was 542. The rear fuel pump isnt vcoming on and that was the fuel tank i used. The front one turns on i alread put gas in it but it still wont start. I checked spark and its good. I dont know what to do next.

Codes 114 and 116 are most likely caused by not warming up the engine before running the tests. Code 121 is interesting: TPS voltage above or below expected voltage. If the TPS was shorted internally it could be sending the VREF signal to the PCM. This in turn would cause the PCM to shut off the injectors during cranking. This is a built-in feature to clear a "flooded" condition. I would measure the TPS before going too far.

Use this for reference: Ford Fuel Injection » Throttle Position Sensor (TPS)

I think the 542 is why it did what it did.
That would be a bad fuel pump or fuel pump relay.

My suggestion of the TPS problem was based on the assumption the front is actually working and supplying the proper pressure. To Bill's statement: never ignore the obvious.

It starts right up with starter fluid and i changed fuel filter it was clogged. There are only drips coming from the fuel line going into fuel filter so i dont know if the pump is clogged and not pumping alot of fuel i put in 5 gallons of gas and that should be enough. I know for sure the rear pump is dead bc i cant hear it turn on but the front i can.

I would take the bed off and then pull both pumps (Fuel Delivery Modules [FDM]) and see what is in the tanks and bench check the FDM form each tank.

The tanks may need cleaning and the fuel lines from the tanks to the fuel filter may need to be blowen out with air.

I never thought of pulling the bed off to get to sending units. How hard is it to pull off the bed? I cursed and cut myself etc. laying on my back in the driveway replacing a fuel pump on my old truck....

Some time it is not too easy.
You may have to PB blast the nuts and let them soak for a day or so.
I also run a thread chaser over the threads before I try to back off the nuts.
The you need three other guys to help you lift the bed off.
But the fuel system is much easier to work with once it is off.

That makes sense bc the guy i bought from said it sat longer than ran but it fired right up when i went to go look at it.

Since the metal lines are such a pain in the but to remove somtimes can i just get some rubber fuel line and hose clamps? And also how many bolts usually hold the bed on?