Questions and Answers

Chevy G20 Van Fuel Pump Q. Dear Vince, I have a 1991 Chevy G20 Van, 350 TBI, 200,000+ miles. Problem, driving 60 miles per hour 30 minutes then started jerking and sputtering to a stop then would not start. I have verified the problem is in the fuel system by cranking engine with the fuel line disconnected from the fuel filter under the vehicle. I have checked the fuse for the fuel pump, which was good.

I would just like it if you could tell me everything I should check before dropping the tank to replace the fuel pump and how to check them. Also should this vehicle have a fuel regulator? If so, where would it be located? When should the fuel pump have voltage? I am old school and not familiar with electronic pumps. The way I verified it is a fuel problem is that it will run fine when fuel is added manually.

Thanks for any advice,
Lonnie

A. The pump in the gas tank is probably shot. When you turn on the ignition, you should hear a click from the fuel pump relay. It is controlled by the ECM. This is known as the two second prime. It will turn on pump for two seconds and shut it off if no crank signal is seen. There is a plug near the tank with three wires. One wire is ground, one is for the gauge and the other is for the pump.

With this plug disconnected and a test light to a good ground, probe all wires on the body side of plug for juice when the key is turned to ON. One of them should light for two seconds and turn off. If it does, the relay, ECM and wires are okay You will need to drop tank to replace the pump.