Hey does anyone know what a stock 600 hundred motor should be running for fuel pressure. I have a quadzilla fuel and rail digital gauge and all i have seen is 7 for fuel at idle, and as soon as step into it all is gone running with everything turned off, on, and even with my quad plugged in. i need some help i got beat by my friends duramax running with a edge hot juice.

 

hmmm...sounds like you need a new lift pump...7psi is pretty low for idle with only a quad box...

 

i see 9psi at idle and down to 5 psi under wot smarty on #7

 

hmmm...maybe I am wrong...I heard that it is bad for the pump to be under 5psi...is that true?

 

ya i dunno i heard it wasnt as big of deal on these new common rail engines

 

My '05 Zilla RPG starts at 0 with the key on and idles between 4 & 5, but it's always moving around. My "rail pressure" flutuates in the 6300-6800 psi range at idle. Where is your "rail" pressure at idle? I've checked the high end after driving and only ever seen a high of 8 psi once. The highest "rail" pressure I've seen is 26,820 or something like that. Not sure if this helped you any. Check my SIG...

 

my rail holds there right there with yours right under seven grand and i havent got quite 26,820 but with my quad xzt i have seen right at 25000

 

im running fass and it stays around 16 to 17. i dont know if its good or not. That rail pressure gauge i got is trash i think. When i hook it up to the fuel rail sensor the truck runs like crap and when you turn the motor off the engine rpm raises then shuts off. And with the sensor connectors unhooked from the sensor, (just dangling) im still getting readings. I dont understand what is wrong with it, seems that something is shorted.

 

My stocl lift pump would push 6-8 psi at idle. Man you gotta love the Fuel Boss 14-16 at idle and what eer you want while cruising.

 

Mine idles at 7 as well... Then it drops off pretty quick with some pedal. A little worried for the CP-3 but rail pressure stays up, I have seen a little over 27k. Mechanical fuel system next

 

"hmmm...sounds like you need a new lift pump...7psi is pretty low for idle with only a quad box..."


No, that's actually quite normal, my stock pump puts out 8psi at idle, I can draw it down to 0 with the BDTD set to extreme and my right foot planted.