I have a 2003 Chevy Tahoe. To start the vehicle cleanly, I must turn the ignition to the auxillary position and wait for approximately 2 to 3 seconds before continuing with cranking. Durning these few seconds, I usually hear the sound of a small motor operating. I have been told that this is the fuel pump building pressure. I hear it for a few seconds, then it stops and I can continue with cranking. Every once in a while, I won’t hear the sound and the vehicle will not start on the first try. Is this a sign of the fuel pump going bad, or something wrong with the electrical circuit that controls the fuel pump, or possibly some other condition? The vehicle exhibts no other symptoms during driving. Suggestions will be greatly appreciated, thanks!
A good mechanic will be able to check the fuel pump pressure, fuel filter and fuel pump wiring for you. If you are not hearing the fuel pump at times it could be a bad key switch, loose wire or more commonly, the fuel pump is starting to fail. The Tahoe needs to be checked out. If the fuel pump dies then the Tahoe will have to be towed which is added expense.
If it does not start and you do not hear pump take a rubber mallet,your foot or a good sized stick and hit gas tank.
This sometimes works if pump is going bad or if there is loose wire on pump.
Also when you can keep tank near full.
There is also a relay in the circuit and you may be able to have repair guy switch another relay, maybe rear defroster relay. It has to be same size.
There is also a type of drain back valve to keep gas from going back to tank when it sets.
After it sets repair guy can check line pressure to check this.