Commanded Rail Pressure

[LLYD_MAX]

Ok so im having some problems with my fuel system. Im trying to command 160mpa but when i command and log try to log it the log shows im only commanding 38mpa max? am i not leaving it at 160mpa long enough for the log to pick it up in a freeze frame? Or is my Cp3 really weak? i only leave it at 160mpa for like 5 seconds bc the truck sounds like its about to blow up. I know my FPR is bad but would this have anyhting to do with not getting the desired rail pressure? thanks in advance for the help

 

[Chevy1925]

Ok so im having some problems with my fuel system. Im trying to command 160mpa but when i command and log try to log it the log shows im only commanding 38mpa max? am i not leaving it at 160mpa long enough for the log to pick it up in a freeze frame? Or is my Cp3 really weak? i only leave it at 160mpa for like 5 seconds bc the truck sounds like its about to blow up. I know my FPR is bad but would this have anyhting to do with not getting the desired rail pressure? thanks in advance for the help

that is what physically commands the fuel pressure so yes

 

[JoshH]

Ok so im having some problems with my fuel system. Im trying to command 160mpa but when i command and log try to log it the log shows im only commanding 38mpa max? am i not leaving it at 160mpa long enough for the log to pick it up in a freeze frame? Or is my Cp3 really weak? i only leave it at 160mpa for like 5 seconds bc the truck sounds like its about to blow up. I know my FPR is bad but would this have anyhting to do with not getting the desired rail pressure? thanks in advance for the help

What is the actual rail pressure? I'm guessing you're using the DVT controls in EFILive?

 

[McRat]

The truck will barely run if you max the rail pressure at idle. Don't think it hurts anything, but sounds like crap and will often die.

If you can command your FPR to make the engine sound like arse at idle, it might be fine.

The FPR works "backwards". When no current is applied, it's full-blast. When you apply max current, pressure is very low.

 

[LLYD_MAX]

Sorry i should have been a little more clear. I know my FPR is bad and i know it causes the truck not to idle right and causes the rail pressure to spike. Im running the rails dry on a very wild tune and im trying to find out if its the CP3 causing it. Im changing the regulator next week and i wanted to see if the cp3 is going out so i can change it while i have everyhting apart.


I saw a few threads where you can test it by using the DVT and commanding 160mpa and seeing if the rail pressure actually goes that high and holds. The Log doesnt show the rail pressure even close to 160mpa. The rail pressure at idle was anywhere from 4800-5200 psi at idle since the fpr is bad. Im trying to find out if my cp3 is going out on me. so what would be the normal rail pressure at 160mpa? 25,000-26,000?

 

[LLYD_MAX]

The truck will barely run if you max the rail pressure at idle. Don't think it hurts anything, but sounds like crap and will often die.

If you can command your FPR to make the engine sound like arse at idle, it might be fine.

The FPR works "backwards". When no current is applied, it's full-blast. When you apply max current, pressure is very low.

thanks for the info i learn somthing new everyday over here. I didnt figure it hurt anyhting but when when the injectors get loud and the truck shakes it makes me cringe lol

 

[S Phinney]

160 mpa is approximately 23,000 psi. Look at desired and actual pressures on a log and you will know whats up.