I picked this truck up for $50.00 hoping that I could get it running. The person who had it before me said the fuel pump quit running so he dropped the fuel tank and hot wired the fuel pump it worked so he put everything back together, but if you turned the ignition it wouldnt run. So he took it to a little shop. A mechanic said that there was a short in the wires somewhere and started cutting. Once he figured he was in to deep he called the previous owner and said that it was going to cost $900.00 to find the short. He said no, so they taped the wires backed together. Thats when I got it. Well with ignition broke that was the first thing I replaced, still no fuel pump. I got under the hood and found a mess of wires taped so i fixed those still no fuel pump. So the next thing I thought was the fuel pump relay so I replaced it and again still no fuel pump. Upon further inspection of the connection that the fuel pump relay goes into I noticed that the wires to the connector for the relay were exposed and almost decayed through. So I went to the junk yard and got a connector, installed it, put the relay switch on and still no fuel pump. So I started testing the wires on the relay connector I had postive going in when the ignition was turned on and the power would go out when you turned the key off, But I didnt have power going out of the relay to the fuel pump. My thinking is bad relay, well after three relays you start wondering is it really the relay? Next I checked the wire for ground, it was explained that it was a positive ground not negative, so I put a jumper off the positive post and sure enough the fuel pump started humming away. I was unable to find where the short was in the harness so I tapped into a wire out of the ignition cluster to give me that positive when I turned the key on and wired it to the relay! Amazing it started and ran for a while, I put it outside and let it run for a little while, keeping in mind it had sat for a while, months without being started you can imagine the smoke it was putting out, then it was like it was choked out, died and wouldnt start again. The fuel pump is still working too! When you spray starter fluid in where the air intake hose connects, it would start but wouldnt run on its own even if you gave it gas. So, by NO MEANS am I a mechanic and I am lost now. I would appreciate anyones suggestions! Thank you,
"EBAY"

 

If it starts with the starting fluid sprayed in the throttle body than the issue is Fuel delivery. If it is fuel injected than the fuel injectors may be cloged up due to the old gas that was in the tank, or if carb than the fuel floats may be stuck. I would check to see if you have the correct fuel pressure going to the Fuel rails or carb depending what you have as a engine. Also might want to try to change the fuel filter very easy to do and may help.