1990 gmc sierra sle 5.7 tbi
I have no power to the fuel pump ive put new fuel
pump in nothing replaced relay still nothing
replaced fuel filter injectors ecm still nothing
fuseable like fuse is good truck has spark but will
backfire if. You put to much gas in the tbi I ran a
wire to a toggle switch then to fuel pumps hot wire
it primes it but the injectors dont receive power
either doing I need to replace the icm and the
distributor?
note the diagram for fuel injector, top injector, voltage wire is red. In the diagram, the bottom fuel injector, voltage wire is white. Those wires go hot with key on, and fuse protected. Did you check voltage at wires, key on, use a test light. If no voltage check the inj fuse. If voltage and you suspect the ground, the pcm grounds it. Check for rpm signal before replacing anything.
Just to add, the purple wire with white tracer carries rpm signal from distributor to computer, engine cranking check for a signal on that wire, dc pulse. If you have digital multimeter with tach--duty cycle any of that should react to dc pulse. If nothing on that wire, have to dig further. Just my opinion.
