Rail Pressure Question

[donnier]

I v installed a rail pressure gauge on a stock 05 mounted off the bottom of the filter housing.

When idling, the gauge shows 8#. Drops to 7 on light throttle and

when doing 70.

At WOT, it goes to 5#.

Is this normal or is there a problem?

Thanks.

 

[JasonCzerak]

That's not a "rail" pressure gauge. that's the lift pump or low pressure gauge you are using.

As far as pressure, 8 is a tad low. should be about 9psi with an 05 in tank pump. how many miles on the truck? When was the last filter change?

So long as your not hitting 0 pis at WOT tho, you should be good. if the idle and WOT psi numbers get lower (with a new filter in place), then have the pump checked at hte dealership and considered for replacement. If you are out of warranty, an AirDog or Fass unit is easily installed.

 

[donnier]

My mistake, Coffee hadnt kicked in when I posted.

Iv got 43,000 on the truck.

 

[JasonCzerak]

My mistake, Coffee hadnt kicked in when I posted.

Iv got 43,000 on the truck.

I'd say your fine. just make sure at it doesn't drop much. And being in Cali, temps shouldn't be a big factor. My pressure with my air dog can get up to 40 with a 30psi spring when the fuel is thick at -15



until you start putting some fuel to the motor, don't worry.

 

[oneshotkyle]

you'll be just fine with those pressures. the pump in your 05 is high volume low pressure. i used to have just 7psi and still made 561hp with no problems.