been working on tr several days . started problem pulling trailer tk would stop pulling recover and go on .later set code and go to limp mode. first code high fuel rail pressure,rpl fuel rail sensor,next code low fuel rail pressure ,rpl fuel pressure reg ,next code low fuel rail pressure on demand. the truck needed injectors ,rpl injectors same problem . note the return flow very low, found air in suction line rpl filter housing no more air ,rpl cp3,same problem but increased return flow .replaced all rubber hoses vac checked line pump to filter ok. same problem . when the problem first started the truck at acceleration would run good for100 feet and fall with injector noise. know at idle as in increase rpms the actual fuel pressure stays close to desired untill 1500 rpm then falls and injectors sound off, as you can tell i sure need help, thanks mike

 

kind of had to follow whats going on here but i will give it a try.

you replaced all eight injectors, the CP3+regulator, the fuel pressure sensor, all of the rubber fuel hoses and the filter housing and you are still getting low fuel pressure codes?

my first guess is you are getting air in the lines or have a kink in one of them. double check that you dont have any restrictions at the pickup in the tank. it is possible that one of the new injectors is bad or some contaminants got in when you where replacing all of this and is messing with the injectors

what do you mean by the "injectors sound off"? are you saying start to knock?

 

I had a buddy with similar issues and ended up being collapsed fuel lines in his tank. Fuel Optimization (injector sound off) ? I think is what Mike was saying.

 

as in: Deceleration fuel cut off (DFCO) while coasting?

 

Srry wrong use of word. Can't think of word I was after. But it's when u have deluded fuel or water in the fuel and creates knocking.

 

when it is knocking does it smoke more then usual?

 

thanks for the help
no smoke when the injectorssss knock ,they knock as i increase rpm to 1500 .replaced all rubber fuel lines , used remote fuel tank, mounted cab level ,hooked to fuel line at fire wall ,same problem .last checked no codes set . thanks

 

i wonder if you are having a MAF, BARO or Temp sensor issue

 

Would batt grounding out possibly create computer to be goofy like that. A guy i know is having same symptoms he replaced cp3 and all the fuel lines. His truck was running good but then we spotted coolent leak and while he was in engine bay ended up grounding the batt out. It has been showing the same symptoms as yours but we are still working on it.

 

its possible. arcing creates high voltage spikes so that may have damaged something. another ECM is usually needed to test this. have any other trucks you can borrow from?