so the truck has been loosing rail pressure under acceleration for a while now. Checked rail pressure sensor, relief valve. Replaced fca, cascade with the arson kit. Still no better. Finally gave up and put a differnet cp3 on it.
It fixed the loosing pressure problem. Will hit 22-23k pretty easy now, but wont go over that, smarty set on sw7 or 9 trq 3 rail stock timing 2 and wastegate off. The truck runs good but still not 100% i believe. Also only will hit 34 psi of boost or so, used to hit 43 easy. So wondering what the other possiblities could be? any help or ideas would be good.

 

sounds pretty normal to me. my 07 5.9 would not go much over 23k unless rail psi was turned up with smarty and boost looks normal. if you were getting 43psi out of a stock turbo, it won't last long. don't see a built tranny in the sig either. tq on 3 and running smarty on 7 to 9, tranny won't last long either.

 

Cbrahs,
thanx. Mayb I'm just forgetting how it did run. Been fighting the loosing rail pressure for quite sometime, just too busy working and lack of funds.
And yes I know about the turbo and tranny, only get heavy on pedal a few times then turn it back dwn. My tranny fund is comin along but still a ways to go. Along with replacement of whole host of goodies.

 

Yeah my stock truck only sees about 23-24k on the rail and I can only get mid 30's for boost which I am ok with. I thought it was a little low two but I have to keep reminding myself my other two trucks were modded so I can't compare numbers .