I need some help. My buddies 1998 S10 Blazer will not run. When you hit the key the engine turns over and starts normal but dies right away. It gets gas from the initial priming but that's it. It will do this all day long. The fuel pump was replaced 3 months ago, you can hear it running as soon as you turn the key on. We disconnected the fuel line after the filter and turned the key on, the fuel pump started and there was plenty of flow. We did this several times very quickly and the fuel flow was strong every time. If you spray starting fluid in the throttle body after it's started it will stay running so it is a fuel issue of some type. Is there a separate relay or pressure switch that controls the fuel pump once the engine is running? Could it be a wire in the ignition system? Any ideas will be greatly appreciated.