fuel pump presure
- Thread starter ellis
- Start date
alienturtle
Human
Are u running an electric pump or the stock lift pump?
alienturtle
Human
The stock lift pump puts outan ave of 7 psi. Iv never seen them jump psi when the vehicle is shut off. Doesnt sound like its your starting issue though
icanfixall
Official GMM hand model
Pressure sounds great to me...
alienturtle
Human
Dito 
well i went back out there and it was on zero but as soon as i turn her over she went right back up . it must be when it sits all night the presssur is droping will it go back through the fuel pump well the pressure gaude was a plus takes alot of guess work out of things ill keep you posted thanks
alienturtle
Human
the lift pump is mechanical and it bolted to the right side of the engine. It has an arm sticking out of it that goes into the block and rides on the cam. The pump is only pumping when the engine it turning over or rotating. To my knowledge there is no "check valve" or any kind of device to stop fuel from flowing backwards. There are a couple problematic places in the fuel system. The most common instance would be the return line caps/orings and lines. When was the last time those were replaced?
GenLightening
Yeah, it's a CHEVY!
The pressure rise may be due to when you turn the key off, power is shut off at the IP but the engine may continue for a revolution or two which continues to actuate the fuel pump. Seems normal.
well i put new caps and orings about two years ago along with injectores and a pump. so ill let it sit tonight and see how she does when it is warm out like it was today she fires right up even after setting for a few hours i dont even have to glow it my glow plugs are on a button and have been for 3 years it mayby time for new orings but i do have alot of blowby and it does use oil so i know the rings are going south but i am just trying to wait to get into the motor for now. but i do like knowing my pressure and the gauge works good.thanks
