Wife's 89 mustang is having some kind if weird problem where it won't start. The car sat unused for almost a year. Turns over, has good compression, but won't start. Wouldn't even run with starter fluid sprayed into it. Called in my father inlaw mechanic (retired big truck mechanic). He's baffled. Has tried: Changing fuel filter Checked the timing Checked the distributor cao and plugs/wires Checked the fuel pump The pump cycles for a few seconds then stops- i remember it always doing that- a very audible brief run, which i assumed was building pressure in the line. It has been changed, less than 20,000 miles ago. He has wired the pump to direct current and confirms it will run longer. Question: is it supposed to run longer than a few seconds? He has since been able to get the car to run briefly with the tank off, direct feeding fuel into the lines. Anyone have any ideas on this? Could there be some kind if valve ir sensor that's gone bad preventing fuel from making it from the tank to the engine?