I have a 2002 GMC Sierra 1500.
The truck had stopped, and it appeared to be the fuel sending unit
That unit is a canister containing the fule pump as well, and goes for about $400 retail.
To get the truck back on the road temporarily,
We changed the fuel pump (not the whole canister) and "hot wired" the fuel pump to a switched ignition 12v (fused) source.
The first time this was done, it worked fine for 1 week
(the pump burned out) .
We bought a new fuel pump and tried again.
This time, its working, but it takes 3-4 cranks before it starts.
It seems that the fuel pressure must be off, but we have no way to verify this.
1) What does the sending unit do ?
2) How many volts is the fuel pump?
(i checked the voltage at the sending unit and it was only 5 volts)
Any ideas for a solution ?
The fuel sending unit only controls the gas guage not the fuel supply to the vehicle. The pump is twelve volts. If you are not getting twelve volts on the PUMP wires check the fuel pump relay and the key circuit to it. If you have to cycle the key three to four times rapidly to get the vehicle to start check the fuel pump pressure at the regulator for manufacturer specs. An injector stuck open will also cause same problems you are describing.
795 views
Usually answered in minutes!
×