1992 s10 blazer fuel problems

[ikeym]

My 92 s10 4.3 wont start -- its not getting gas and i changed the fuel pump relay.Im trying to check the power at the connector before it goes in the tank.2 wires one purple one green -- im asuming that the larger green wire is the hot wire for the fuel pump -- so the purple wire only has 8 volts with the key in the on position and the green has none.My question is should both wires have 12 volts with the ign key on?Is the another way to check the power?

[jjw879]

Hey, I can help you, tell me first, do you have central port injection or throttle body? If your not sure, you can tell by the VIN, There is either a w or z in it. Or if you open the hood the upper intake plenum will say vortech or it wont. Let me know and I can tell you everything you need to know. Its really hard to tell if a pump is bad by volts going into it, because there can be other problems. Do you have a fuel pressure tester? if so test with that, as both CPI or TBI Have different pressures at key on. Also have a friend turn the key all the way before start (key-on) and lay under the tank itself and listen for a humming. If there is none, pumps bad. Central port injection requires a lot of pressure and even a few pounds short will not allow the motor to run. TBI is a different story. Let me know .

[Schrade]

Originally Posted by ikeym

My 92 s10 4.3 wont start -- its not getting gas and i changed the fuel pump relay.Im trying to check the power at the connector before it goes in the tank.2 wires one purple one green -- im asuming that the larger green wire is the hot wire for the fuel pump -- so the purple wire only has 8 volts with the key in the on position and the green has none.My question is should both wires have 12 volts with the ign key on?Is the another way to check the power?

Yes, there's another way to check the green wire to see if it supposed to have voltage, or if it's a ground. Put the multimeter on impedance, and see if there's continuity with the frame. If so, it's a ground wire. If not, there's the problem.

A ground is always connected to the ground, unless there's another switch 'downline'.