I had issues with my F250 cranking last winter when the temperature dropped, so I changed out the glow plugs in the spring. I hadn't been able to truly test them yet, since it hasn't been cold, but the other morning my truck wouldn't crank up. It was 40 degrees out the night before, and it had been almost 24 hours since I cranked the truck, but it seems to me like the truck shouldn't have an issue in that mild weather.

I'm not sure what I need to do next to try and fix this problem, it's been driving me crazy and risks stranding me if I park for a while in an area where I am unable to plug by block heater in. The truck cranks fine when I have had it plugged in for a while, so I'm fairly certain it's a heating issue. I haven't done any tests since last year, but I know that the GPR was working properly last winter, which is why I changed out the glow plugs. If anyone has any advice on what this could be please let me know.

 

If you mean won't turn over when cold, could be batteries when cold or bad starter. Did you retest the GPR, mine worked one minute and then hours later only stayed on for a few seconds. Had to plug it in till I replaced it. Thing was I was on a hunting trip, so I had to figure out what was happening quick.

 

My 01 wouldn't start on a 90 degree day without being plugged in for at least an hour. Tried every damn thing that I could find by searching on here and nothing worked. My research and process of elimination has led me to the injectors and specifically the poppet valve. All 8 have been pulled and are being rebuilt. Hopefully you won't have to go that route.

 

The first thing to do is troubleshoot your GPR. New, old doesn't matter. The second step would be to ohm out the glow plugs to insure that they are working.

 

Hopefully you used Motorcraft GP's. If it's 60 degrees or so, you don't need the GP's to start, assuming everything else is in good shape.