Engine/Transmission (1998.5 - 2002) FASS DDR pressures?

[HD-J78]

Installed the FASS DDR in my 2000 when I replaced the VP44. Was wondering what kind of pressure you are all seeing? I am showing about 22-23psi at 60mph. I got about 15psi under hard acceleration. I don't think that I have yet gotten it under full power yet, wot.

Thanks.

 

[rasteck]

That sounds good. You want to stay at 7 or higher to save the VP44.

 

[tolmsted]

Installed the FASS DDR in my 2000 when I replaced the VP44. Was wondering what kind of pressure you are all seeing? I am showing about 22-23psi at 60mph. I got about 15psi under hard acceleration. I don't think that I have yet gotten it under full power yet, wot.

Thanks.

I installed the FASS DDR a couple weeks ago and it also started out at about 22-23psi. It has settled down to 18-19psi at start up idle and will move down to about 15psi at 65mph.

 

[MAYoung]

As reference, I installed a FASS DDRP in my 1998. 5 2500 after the lift pump started to drop below 6 psi. I now idle at about 15 psi and drop to 13. 5 psi with a wide open throttle. I asked around at the time and most said that is what I should expect. Two years ago it was a little stronger when new but the pump has held up well. Working as advertised.

 

[Ncostello]

From years past... I think 22-23 psi is definately the upper end of comfortable for a VP44. Too much and you'll blow some seals won't you?

 

[JR]

I run 22 psi at idle and about 19 psi at 55-60 mph. The overflow valve in the return line is set at 14 psi so anything under that and your not circulating fuel through the vp your only supplying fuel to it. We all know heat is one of the biggest killers of the vp so it only makes sense to supply enough pressure to keep a steady stream of fuel through it to keep it as cool as possible. I dont have any proof that it will make them last any longer, but it makes sense to me.

 

[Bob4x4]

Most vp's will hard start above approximately 20 psi. so I am guessing your pumps do not hit that 20+ psi immediately on cranking

 

[JR]

Generally the lift pump doesnt start running until after youve turned the ignition over. It wont run with the key in the "on" position while waiting for the grid heaters to warm up.

 

[LNaugle]

yes you can deffinetly blow the front seal and fill your motor with diesel, i would be careful in that range because psi could spike and cause this to happen.