I have an 87 f150 with dual tanks. when i turn the key, it will turn over, but not start. i can normally hear the pump, but not this morning. it doesn't matter which tank i select. it's done this twice before, but then after awhile will start. the first time, the engine was cold, the second time the engine was hot, and this time was cold again. i've tried wiggling the wires on the rail pump- nothing. i hear the relays, but is that a true indicator that they are working properly. i read a similar post, and someone suggested a coil. any suggestions?

not entirely sure, but if you need a coil, check www.f150aftermarket.com (http://www.automotiveforums.com/vbulletin/www.f150aftermarket.com)

On this year Ford the big terminals are for the fuel pump. The two small terminals are for the coil in the relay. I have made a jumper with some no.12 wire. If it runs buy a new relay. If it don't buy a new pump.

Thanks for the input, but i think i found the problem. sometime in the past, the inertia switch shorted and burnt, and the person who had the truck before me simply bypassed the switch and spliced (badly, i might add) the wires together. so i put a wire connector on and haven't had any trouble since. i've also found that the truck runs better, like the pump wasn't getting the voltage it needed during acceleration. i'm confident i won't have anymore trouble from here on out. i also replaced the relay, just to be on the safe side.