Sounds like your resistor is bad. The signal that goes to/from? the injectors passes through the resistor that separates the signals into inj. 1 & 3, and inj. 2 & 4. Sounds like the side that sends the signal to the injectors. If you look on your passenger fender, it should be there, and covered with heat sink fins. There should be two plugs that hook into the harness coming out of it.
There should be two plugs. Unplug them both. One should one terminal (+B), and the other with two (No. 10 & 20). With a Ohm meter, measure the resistance between +B and the other terminals. +B is the input to the Solenoid Resistor, and No. 10 & 20 is the output. You should be able to get between 2 - 3 ohms each. And this is if the output of the ECM is putting out. And ohm meter is your best friend, and the FSM. Which helped me out ALOT!!
Bold type is quoted from FSM.