sounds like air leak
Hello, i have a 97 12valve it currently has 83000 miles, and im having what sounds like an air leaking or sucking issue. it sounds like its coming from the lift pump. it started at about 75000 miles thats when i completely deleted the fuel preheater because i thought that was the problem and it wasnt. if i reach down and pinch off the fuel line with my fingers before the lift pump the noise will go away untill i let it go then itll come back. the fuel line comes from the tank directly to the lift pump. and the noise will go away everytime i mess with the fuel system, like when i replaced the fuel filter, but comes right back after i take it for a spin. it has no fuel plate, star wheel is all the way forward and the smoke screw is all the way in. the problem doesnt really seem to affect the power but i cant tell since its been getting progressivlly "worse". any help would greatly be appreciated. i really dont want to take it anywhere cus im low on funds and i like fixin my own stuff.