• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

fading fuel rail presure

1

1chevy02

New Member
Messages
17
Reaction score
0
i have an 02 lb7 i am running no lift pump and about a 150 efi tune Lately my fuel mileage has been dropping and ive been getting greyish smoke. I used to be able to hold 18000 psi or so rail pressure under full throttle now with the tune it will fade to 8000
mad.gif
I put a new fuel filter on didnt help much. I tried the stock tune and it would only hold about 11000. If i command it to 23000 at idle it will only go to 15000. I have a lope at idle and i didnt know if replacing the fuel rail pressure regulator would help it hold more pressure or not. the lope will go away when i run 2 stroke oil. Or do i need a new cp3
__________________
 
Sounds to me like your fuel pressure regulator is going out the window. You may also want to check your balance rates because there is a possibility of injector problems
 
Check FPR.

Also is this your tune or a purchased tune? How much pulse width is it commanding. Does it smoke a lot of black?

Your truck could be fine and its just a very bad tune.
 
Log it on EFI Live. Make sure that it doesnt fluctuate much, sorry cant remember off the top of my head how to do this.
 
take to dealer and get them to check the injectors i had the same problem on my 02 duramax.. found out it was the injectors.. had them replace then the cp3 pump went so i sold the truck lol.. but have them check.. if you has efi you can datta log it and watch the injectors pulse and see what the numbers are at idle.. if they are way off then they are bad.. you can also try to do the return rate but it is done manually.. if it is high the injectors are bad.. hope this helps
 
i had the same problem .loosing rail pressure and could not find out why .so i started riping into it all my balance rates were good but it was fuel returning to the tank .better hurry your 7 year 200.000 miles might be up i was out just a week and i got screwed by gm
 
You must log in or register to reply here.
Back
Top