1990 GMC Sierra

Bailey 5542 · October 6, 2016

How do you do a fuel test on a fuel pump

nht mike · October 8, 2016

Remove the fuel fill cap. Turn on the ignition. You should be able to hear the pump run in the tank for about 15 seconds. If you don't hear it get a 2X4 or a large dead blow hammer, and tap(!) the bottom of the tank while cranking the engine. A lot of times that will jar the pump and get it going. If that doesn't get it started, remove the wires from the top of the tank and check for 12 volts when the ignition is first turned on.

Mike