Chevrolet Repair: 92 blazer, fuel guage, jumper wires

Question
Hello, My question is I recently purchased a 1992 gmc jimmy with a bad 4.3. I tried starting it to just move it, it will run by pouring gas in the throttle body. The previous owner said it ran when parked.  Any Ideas? the current motor is knocking in the lower end. but how can I "hot" wire the fuel pump to see if this is what that particular problem is? thanks Jim

Answer
Hi Jim,

I bought a repairable Explorer that supposively ran while parked.  I couldn't get it started.  I started the usual trouble shooting ideas and nothing worked.  Then the guy who was selling the truck told me he thought it may be out of gas.  I put in 2 gallons and it ran beautifully.  So I have to ask...DO YOU HAVE GAS IN IT???

If you have gas, then why is the fuel pump not working?  Fuse, Relay, or just bad.  You can test the fuel pump by running positive and negative jumper wires all the way back to the harness.  It may just be bad.  Another thing that comes up is vapor lock.  Take the gas cap off and see if you can get fuel.  

Is it possible you are getting fuel, but it won't spray?  There might be a place to hook up a fuel guage to the throttle body.  If so, check for fuel pressure.  My guess is the pump may be bad.  If you can't hear it whining for only a second, with the key on, and the fuse and relay are good, it is probably dead.  

Hope this helps.

C J S