What should the fuel pressure be after the filter and before the IP with a stock lift pump? Thanks

 

Hello,

My 06 when stock has about 8 to 9 at idle and then runs about 9 to 10 running down the road. Wot it drops to 5. All is the same when the Big G is plugged in except the Wot drops to 0 after 4 seconds.

Damon

 

Damon, the 1st gen lift-pump is an entirely different animal from the '06

Montana, the FSM is kinda vague in it's description of the performance characteristics.
- The minimum lift-pump output pressure is 3psi. Lift-pump output volume is 0.70qts per 30 seconds of engine cranking.
- To test the lift-pump, the FSM has you Tee a vacuum guage into the fuel line coming from the tank, and into the lift-pump. With the engine operating at 1500rpm for 30 seconds, the vacuum should not exceed 3.75" Hg. (If it does, look for a stopped-up fuel pickup).

- The maximum allowable pressure drop across the fuel filter is 3psig.

- If there's any fuel leakage on the exterior of the lift-pump, or you notice the engine lube oil level rising inexplicably, replace the pump.



Hope this helps.

 

A healthy stock pump will put out 7 or 8 psi at idle.

 

Thanks guys thats what I needed to know. Just installed a fuel pressure guage and new filter and wanted to know how much psi I was looking for. I guess my lift pump is in preyyt good shape. Thanks again