heres the problem...my grandad drove his truck through the weekend...and monday it wouldnt start, so he assumed the fuel filter....still nothing....changed the glow plugs still nothing....tach moves up and down while tryin to start...so no Camshaft sensor is need right?...will start on ether for a bit, then die after about 3 secs like there is no fuel....checked the fuel pressure....and its 45psi while tryin to start....BUT it bleeds back down...is this normal??...what else could it be....(Im tryin to do process of elimination so it doesnt cost him an arm and a leg) THANKS!!

 

First thing- How much oil is in it. Powerstroke injectors are fired by high pressure engine oil. If it gets low, the pump wont pick it up. Second, just because the tach moves dosent always mean that the cam sensor is good. Have you checked all the fuses under the hood?

Also, NEVER use starting fluid on a diesel with glow plugs. If the glow plugs are working properly they can ignite the either with very bad results.