7.3 wont run when cold

[doomachine]

i got a 2000 f 250 7.3 that will not start when oil is cold runs perfect when block heater is plugged in for an hour new HPOP; GPR; and new glow plugs

[JSchuricht]

What is the outside temp? Have you checked that your glow plugs are actually getting power? How long do you wait after turning the key to run till you turn it to start? Are you seeing a bunch of white smoke when you try to start it?

[doomachine]

around 30 to 50 right now but it does it even in 60's outside glow plugs are getting plenty of juice. no white smoke unless i just keep cranking on key till it starts for 30 seconds then dies

[Trey7.3]

That's what my truck does. But it has bad blowby. Burned 5qts of oil in 400 miles. I'm changing the motor next week

[Turbostang500]

Are the batteries good? It might not be cranking fast enough. If the voltage drops below 10 while cranking, the pcm wont function.

[doomachine]

batteries are good

[Turbostang500]

Can you explain how they were tested? There is a common mistake in testing our truck batteries.

[doomachine]

was thinking LPOP might be getting weak since it has over 300k and im running rotella 15w 40 motor oil

[doomachine]

individually load tested each battery

[Spuddy98]

My truck runs rough when its cold out. A couple days ago I was spraying Carwell on the frame and around under the hood. Trying to get anything metal. Yesterday when I went to go to the drugstore at 9PM and 30 degrees it started like never before. Maybe these trucks have something electrical that needs the moisture driven out? (by water displacing rust inhibitor or your block heater).

Maybe you can douse it with WD40 and see if it makes a difference.