I have a 2000 GMC Sierra. I just replaced the fuel pump. I had to replace it because the fuel sending unit was bad and the fuel pump itself was making a funny noise. Now either the EVAP line or the return line is vibrating along the frame rail. I ran about 10 gallons of gas through it so it can not be air. I am not sure if my fuel tank is pressurizing or not. Could this cause this strange sound? There are no sounds other than the normal fuel pump noise around the tank…otherwise I would replace the fuelpump again. Please help.
Thank You
Maybe the noise you hear is being caused by pump cavitation (something is blocking the pump pickup).
Are you thinking that excess pressure is building up in your tank somehow?
After vehicle shutdown release the gas cap,anything odd happen?
Have you taken a pressure reading? Are the lines secure?
I do not believe that the pump is cavitating because it drives fine and it has 60PSI of fuel at the rail. nothing odd happens after I release the gas cap. All lines are secure. I am not sure if any pressure is building up in the tank. I was told some time ago that the tank is suppose to build 1 PSI of pressure. I do not know how it builds that pressure though.
This is one of those problems that has me scratching my head.
Please help
What controls the fuel flow through the fuel return line? Isn’t that the fuel pressure regulator?
Look into your repair manual for “fuel pulsation dampening”, or “fuel damper”, or something similar. Look at the instructions that came with the fuel pump. It may say that a fuel damper is part of the fuel pump.
For the pressure in the EVAP system, check your manual on the fuel and EVAP sustems.