my hard start is kindof spiratic. Im worried I have a cracked diaphragm in my vp44 is there any way to tell? But, it also wont start hard down hill. I cant find an air leak in my return fuel line. Anyone have any ideas or suggestions.

trouble codes and fuel pressure would help greatly. if you are saying it starts fine facing down hill ther is a good chance you are leaking air somewher. when min was doing it the injector lines wer leaking at the head and letting air in. i can be anywhere not just the return line.

my gauge is on the way from jegs no no dtc on the ecm or pcm so i guess i will find oout when i get the fuel psi

my gauge is on the way from jegs no no dtc on the ecm or pcm so i guess i will find oout when i get the fuel psi

Yep, gauge would help! Keep us posted. Dave

Things to check. Fass/airdog/factory lift pump lines. Like stated injector nuts. injection lines on vp pump. Cracked or bad gasket on fuel filter housing. Return line on back of the head(center of head behind valve cover by the firewall) Return line junction block (follow return line in back of the head) cross over tube rubber o rings injector o rings. If it was me i would do the cross over tube o ring and injector LAST.

Things to check. Fass/airdog/factory lift pump lines. Like stated injector nuts. injection lines on vp pump. Cracked or bad gasket on fuel filter housing. Return line on back of the head(center of head behind valve cover by the firewall) Return line junction block (follow return line in back of the head) cross over tube rubber o rings injector o rings. If it was me i would do the cross over tube o ring and injector LAST.

That should cover it!

today after work i checked out the fuel system checked out and took out some bango bolts checked them out . re torked the fuel filter to 25 foot pounds it looked good after all that it seamed to be good. drove it and went inside and had dinner came right out hard start!! seams to have got worse.

--- Update to the previous post...

i used to have a pressure build up in the fuel tank though it might be o rings but idk i went away only happens in the winter almost like compression in the tank i was told to check the o rings last ??????

as far as the orings last, just look at your cylinder head where the injector lines attach. if they are wet you could be sucking air into the fuel system like mine was. it could be the seal at the connector tube or the oring. that would be the same at any fuel system conection. i have heard of air leaks even where you dont see wetness but have not experianced one yet. i have seen some discussion about pressure building in the fuel tank but dont remeber what causes it.

today after work i checked out the fuel system checked out and took out some bango bolts checked them out . re torked the fuel filter to 25 foot pounds it looked good after all that it seamed to be good. drove it and went inside and had dinner came right out hard start!! seams to have got worse.

--- Update to the previous post...

i used to have a pressure build up in the fuel tank though it might be o rings but idk i went away only happens in the winter almost like compression in the tank i was told to check the o rings last ??????

Are you throwing any codes? Do you know how to check for those?

Dave

my fuel psi is 21 at idle and 15 wot, no coads, i played around with the fuel system pulled it apart, pulled the drain valve out it was sticking the hard start went away for a day, i washed under the hood to get rid of the diesel and it came back.

my fuel psi is 21 at idle and 15 wot, no coads, i played around with the fuel system pulled it apart, pulled the drain valve out it was sticking the hard start went away for a day, i washed under the hood to get rid of the diesel and it came back.

Michael what do you think, too much pressure on the IP diaphram? Would he need a cut off sw?