7.3 Powerstroke wont start after sitting 12hrs or more, any help for me?
 

I have a 99' F350 with 7.3. If the truck sits for more than 12hrs, it will not start. If you shoot a shot of starting fluid in, it will fire right up. Once running, no issues. Can turn on and off no problem during the day. Only have this problem after it sits. I have replaced my glow plug module and cam position sensor in hopes that would correct this situation but to no avail. Please help! Any sugguestions? Thanks guys.

It's possible the glow plugs are bad.

batteries good? Voltage good?

sounds like a fuel issue. like its losing its prime and the either gets the started and the fuel back up to the pump.

batteries and voltage are good.

loosing fuel prime for sure.start tracing your fuel line from tank on and make sure you have all conections tight.also check overflow valve and that should be somwhere at head on fuel return line:humm:

Thanks for the heads up guys, I will work on that today and let you know what I find/dont find. Thanks again.

I would first check batteries and voltage, glow plugs. But don't forget about oil pressure in the high pressure system or the icp sensor, if the system is draining back or pump not building pressure or sensor not reading correctly it will crank forever without starting. Another thing I have seen with the 7.3's is the high pressure oil gets dirty and causes a hard start. Have you serviced the high pressure side recently?

I just bought this truck. I had it 2wks and then it started doing all this. I will run through his service records and check. If not, I will get that done.

Clean oil is by a long shot the most important thing in a HEUI injection system. If you dont know when the oil is changed I wouldn't go any further without changing it. PSD's rely quite heavily on good glow plugs too.