FASS pressure ?

[strokin6L]

I just installed a FASS 95 series system on my buddy's '05 6L that is a stand alone system and eliminates the factory pump(HFCM). The FASS system is said to put out 50psi but the fuel pressure gauge reads 66psi. I started it up and let it idle for a little bit then drove it around the block and it still stayed at 66psi. I unscrewed the filler cap to see if i could hear fuel returning into the filler neck but couldn't. So i unhooked the return line from the pump to the filler neck at the filler neck and it is returning fuel, it is but only a little stream. I have the fuel pressure gauge setup to read fuel pressure at the factory regulator on the engine, but should i have the sending unit at the pump instead? I just don't undertstand why fuel pressure is 66psi when the pump is said to only put out 50psi. The rest of the fuel system on this truck is stock.

 

[Vizsla]

Is it 66psi key on engine off? Oh duh... 1- does it still have the factory regulator in it, they vary, or someone might have a BB in there. 2- Much greater volume can do it, but I have no Idea why. My 10psi Airdog puts out 16psi constant on the gauge. My sender is in the regulator, which is in the return line. Sorry, prolly not much help.

 

[strokin6L]

Yeah it's 66psi with key on and engine off, but also is 66psi when engine running. Yes, like i said the trucks fuel system is completely stock and the sending unit for reading fuel pressure is in the factory regulator on the engine. There is no BB in the factory regulator anymore i took it out before i put the FASS on the truck. Just can't think why it's reading 66psi when the pump is suppose to put out 50psi. Before with the factory pump and the BB in the factory regulator, it would reading 58psi. Now without a BB and a FASS pump that's suppose to have 50psi, it reads 66psi. I'm just not getting it. I don't want to have too much pressure and damage something.

 

[Robts]

Im thinking you might have to switch the spring and maybe the fitting....Seems too high for stock sticks

 

[kmh270]

call fass and tell them you want a smaller psi spring i had the same prob. and ended going with a lower psi spring and it fixed the problem. There easy to install just take your return fitting out of the pump and the spring is right there. the spring w/ shipping isn't over $10.

 

[strokin6L]

Thanks guys i'll try to call FASS monday, i'm sure they're not open on weekends.