installed a new fuel pressure gauge last night, plumbed directly into the fuel rail. it works, but doesn't seem right. at idle, it's reading ~64psi and when i open it up, it drops to ~60psi. i thought the pressures were supposed to be ~55 and ~50 respectively. i have the ground on the sender going directly to battery ground and the gauge grounded to chassis in the cabin. could this be a voltage offset from the different ground locations, and maybe i should run the sensor ground to the same location as the gauge ground?

Pic - Sending unit location

Pic - Fuel Pressure Gauge reading

could just be that its a electronic gauge and wont be as accurate as a mechanical one.

i have a mechanical gauge on my fuel rail, its reads 64 static just like i set it....even verified with 2 other gauges.

Cool. Sounds like i'm reading good then. Thank you.

i have an 04 but dont recall that location to put a fuel pressure sending unit there...did you 'tap' into the end of the fuel rail or did you have a pre-existing location to screw in that fitting?


04 Cav. 2dr. 5spd. My DD. 'Nuff said.

Fuel pressure is almost always listed as "ignition on, engine off"

So basically, key on, let the pump prime, don't start the motor.


That's how I've always seen it anyways.