I have a 98 Chev Astro van. It acted by it was running out of gas the other day, I pulled over, it didn't die. I took gas cap off, put it back on and vehicle ran fine for about 70-80 more miles! Got it home okay. The next day, the vehicle started okay. I had decided to change the fuel filter just in case. After changing it, the vehicle would not start. The fuel pump is not pumping fuel and the vehicle won't start now. I can pour fuel into the throttle body and it will start, but won't stay running because it is not pumping fuel. Does anyone have a clue what is going on?