not sure if anyone can help but 01 f350 7.3 wont start on its own enles you plug it in for a half hour or so then when it starts it sounds like only half a moter. after it warms up it runs just fine i have a heated garage so it dosent get cold in there. ive changed glow plugs and injectors fuel filter and relays but still the same??????

 

Maybe take a video of it...

How many miles?

 

My boss' truck has the same trouble. His is so bad now that it won't start on a 90 degree day at noon without the heater plugged in. I just got an autoenginuity scanner and am going to dig deeper into his now. His has been that way for over 2 years now. The first thing anyone says is glow plugs but in our case that is definitely not it as I have done every test possible and a few others to rule that out. I have also done a compression test, high pressure oil test, replaced the cps, icp and ipr and none of it made any difference at all. It seems to be getting worse over time. I am almost convinced that it is bad injectors in our case.

 

what oil weightl?

 

Did you make sure the glow plug relay was actually sending power to the glow plugs? Its one of the relays next to the fuel filter. One is the intake heater if yours has one and the other is the glow plug relay. I have seen this several times.