Fuel delivery problems?

i have a 92 Isuzu rodeo. the engine will turn over but will not fire unless i dump fuel manually down the throttle body and then turn it over. i have jumped the fuel pump and it runs. the ground is good to the pump, the second wire off of the pump has continuity to the relays(there are 2 fuel pump relays). there is a good ground at the relay sources and power as well. i have tried replacing the relays with the other ones in the fuse box and i have bought a new one with out any luck. the fuse is ok. i am so stumped on this truck, i would greatly appreciate some help on any ideas on how to get my fuel pump to kick on.