i would put a stock delete tune in, test and if that still shows low rail, start looking at the FPR like stated
RIP lml cp4
- Thread starter Tater1
- Start date
When cp4's just get weak they'll still put shrapnel in the system or is that just catastrophic failures?
when they start going, they start going fast and it will start putting steel in the fpr. from there it starts throwing steel down to the injectors quickly after. they generally dont wear out like a CP3 till you get lots and lots of miles on them. if its ran that slow for a long time, it may not be a CP4 but until you start diaging it, we dont know.
Just got three in here that are all failed. A 69k '14 3500 w/t. Chevy garage replaced pump, lines, rails, and injectors under warranty. Also a '12 2500 ltz with 205k. It runs and sounds great but will only make 90mpa. Has one injector balance rate bad. Will be tearing into it next. Also bought one with 119k that someone pulled the regulator and left in the cab. It's covered in debris and no start. Fun fun
