Ford 2005 f 350 super duty 6.0 turbo diesel long crank time cold or hot run air pressure test changed hi pressure oil pump and irp. wont start till the oil psi. gage comes up could the problem be from the psi switch?

first, have an experienced mechanic check your timing.

if timing is still ok, have your fuel injectors cleaned. perhaps some sort of dirt or particle has entered your fuel system.

I have a chevy c3500 with a 6.5 turbo diesel, the times that it has happened

to me was because of a dirty fuel filter or water, most diesel have a bleed off

valve to dissipate any accesss water in the fuel line, on my truck is located

on the right front side of the engine . you bleed it off when the engine is

turned off. good luck

these trucks use a oil fired fuel injector, if your high pressure oil pump has eccessive wear or if your oil to broken down from being run to long between oil change, it will not build enough oil pressure to fire the injector once the oil is thinned out from being hot. An oil leak in your high pressure oil system can cause same problem.

my 04 ford 6.0 doesnt start some times but if i turn the key on for 20 seconds then turn key off and do it again for 20 seconds and the 3rd time it starts but dont crank it over till the 3rd time its been working for me

high pressure oil curcut often d rings in heads high pressure oil should be 19 - 20 percent duty cycle

change the delivery fuel pump right before the injector pump should 100% solve the problem. thanks

check glow plugs.

dies the truck restart once it cools off? it is very common for th 6.0 to have high pressure oil issues on a hot soak. they will run till the cows come home but once shut off they can not build up enough pressure by cranking speed alone to start truck until it cools down and the seals become rigid enough to bridge the gaps they are sealing in the first please. if this is the case. it may be the STC fitting ojn the back of the high pressure oil pump (intake and turbos must be removed to check) or possibly the branch tube o rings have worn. the branch tubes are located under the valve covers and supply the fuel injectors the oil they need to perform their "power stroke"...

It sounds like it has a high pressure oil problem. does the oil pressure gauge come up while cranking? does it start when cold and not when hot? any check engine light?

i had to replace my oil pressure regulator sensor it contols the oil pressure required to have the injectors open and spit fuel, if you replaced it and still no start replace the the cam position sensor