I understand i have two fuel pumps, one it tank and one on frame. the tank is low pressure and the frame mounted is high pressure. does that mean the low pressure pump supplies fuel at startup and idle and the high pressure takes over when you give it throttle?

I ask because for some reason my rig will not start. I have good spark but there is no evidence that fuel is reaching the cylinders. i can hear the pump coming on with the key turned on and i have fuel going to the fuel filter. i have no idea how much pressure i have, i dont have a fuel pressure gauge right now, but i will get one soon. i don't know if i am getting fuel to the injectors either. like i say there is fuel to the filter but i cannot smell or see fuel on the plugs. in the past i've had problems with the rig idling radically at stops lights or low speeds and it will even die on occasion. but it always starts back up and i good to go. any suggestions?

the low pressure pump supplys the high pressure pump for the injectors because of the high psi required by fuel injection...are you sure that the pumps are turning on? i had the same problem with my 89 fullsize bronco and it turned out to be the fuel pump relay