Engine/Transmission (1998.5 - 2002) Lowest safe fuel pressure?

[DirtyDodge]

HI,

What is the absolute lowest fuel pressure a lift pump should put out at wide open throttle before it should be replaced? What does a brand new one put out?

Thanks,

DirtyDodge

 

[SEmerson]

6 psi

 

[BillGotthelf]

I can only answer with my setup as everyones setups uses different amounts of fuel. I had a TST PM3, hx40 and DDIII's. With a new lift pump I would see 15 at idle and the lowest I could bring down fuel pressure at WOT was 8. I believe anything under 5lbs could be detrimental to the life of the VP44. It uses excess fuel for lubrication and cooling and if not enough fuel is available it will shorten its life. With my new setup I needed alot of fuel and installed the FASS system. We flow tested the stock lifht pump and the FASS pump and the FASS pump filled a 1 gallon container 4 times faster than the stock pump-nuff said.

 

[rweis]

I think the old standard was 10# in idle. Some say any positive in WOT. I can agree with 8 or so WOT but not lower. I regulator bypassed mine for 12 idle and 9 WOT pulling 13k 5er, but I only run dd2's and basically an EZ.



I have a spare 3990105 under the seat. When the current lp dies, and the spare dies, then probably will do the Preperator or FASS system. That seems to be holding up well.



Bob Weis