So here we go...

2005 Cummins 5.9 low on power when it reaches temps over 155F scanner shows LOW rail pressure in the 3500 range. flow test says good return when cold than bad when warm.
Kill test was done with cold and all injectors showed good. did the test again after warm and low and behold... still showing all injectors good. thinking torque on the tubes. any thoughts????

here is the lead up.

Bought the truck. 2 weeks later found out the motor was bad. when taken apart. found missing top piston rings on 1 and 6. NO marks as if they were ever put in. ridge was way down also. no marks on the head, piston was not showing any marks. carbon in the ring groove starting to here about others from 05 and 06 just the same.

Motor was at that point rebuilt apparently the decision was made to just have the injectors tested. All were good so back in they went.

I am at this point thinking its the tubes going to the injectors... Hoping that someone knows more than me.

 

That sounds like a loose connector tube issue.

 

X2 Tubes

 

did you fix your problem?