we just replaced the entire fuel system on this truck and it appears to have a leak on each rail. getting P0191 and P0193. does anyone know of a procedure to test the rails for leaks, fittings, etc.? it starts fine cold but is hard to start hot. reminds me of 6.0 . it is a very small leak and we cannot locate it. thank you for helping in advance

 

I did a fuel sys job on a 6.4 and every fitting had to be torqued plus 1/4 turn . Had to use a crows foot for that. Was there a fitting torque value and did it also have a 1/4 turn requirement?

 

yes and it called for additional 90 degrees and we did each line fitting etc by the book

 

and they were new? These lines are on reusable

 

yes they were new. truck will start fine cold. once it warms up it goes to hell. misfiring, almost like it has air in the lines. when you shut it off it takes forever to get it to fire it up again. if you hold the ignition engaged it will spin enough times to finally reach the point where it will idle about 450 rpm then it takes about 45 seconds to go to full idle. after it warms up it has a fuel knock to it. i am not letting it run very long in fear of melting a piston. i have taken it apart again to take fuel samples and no fuel samples have metal in them. fuel is as clean and clear as it could be. i desperately need help with this truck. please someone help me