Fuel pressure

[greasyF250]

Yesterday, I installed a fuel pressure gauge off the back of the fuel bowl. After purging all the air ,I got 37 psi with just the key on . Then when idling it was at 37 psi for about 30 seconds then it jumped up to 48 psi. I now this is normal pressure but I did not know that the pressure would increase after it runs a bit. Is this normal and I'm thinking about the BB mod. Not today , its freezing rain and 31 degrees.

[jesilvas]

Actually normal pressure should be up around 55-75 I think

[greasyF250]

These pressure reading are with a new OEM fuel pump installed by Ford. I read with the mods that you can increase pressure to 55 + but will run into o-ring problems near 70 psi. Normal is 30 -60 psi in my alldata.

[tubular031]

70 is fine and will not hurt anything. I run 70 to 75 on my VO side (Fass pump) and 55 to 60 on the diesel side (factory pump) Pulling a load Ill drop to 45 to 50 on the factory pump.