im going to send you the wiring diagram for the circuit.
you will still need to see which part of the circuit is cutting out, the 12v or the ground pulse.
to do this , you can just use a test light.
start with checking the power feed first.
attach a test light how you normally would and either backprobe the injector or give a little slice in the wire sheithing before the connector (just remember to seal it up with tape after) at the power side.
start the truck... the light should stay lit all the time, if it starts missing and the light is still lit than the 12v feed is ok.
to do the ground pulse check,
test light connector at the 12v batter this time instead of ground and backprobe the negative side.
start the truck.... it should flash.
when it starts missing, see if the flash is cutting out too.
this is the big part, whether or not its the ground pusle or the 12 v
i will upload the wiring diagram in a couple mins,
let me pull it up for you