ok guys I've hit a road block. Here's my situation. Inj #4 doesn't wanna flow any fuel after startup.
On the initial startup signal when the ecu tells all four injectors to shoot fuel at the same time they all work including inj #4. After that crank rotation the ecu switches to multiport port injection meaning it shoots the fuel before the intake stroke for each cylinder. At this moment is when the #4 injector stops flowing fuel.
The ecu will not allow the engine to run if it's not getting a signal from more than one failed injector. I pulled the #3 inj and the engine still started. This tells me the ecu doesn't view inj#4 as having some kind of failure.
I checked the wiring and there's no short.
I checked to see if it got 12v and they all do.
I checked the continuity from the injector to the ecu and it's within spec of the other injectors.
I also swapped the harness between #3 & #4 which causes the #3 inj to follow the same pattern. This tells me it's not the injector itself.
It's not a tipover, kickstand, neutral, safety issue because the engine does run.
I thought the ecu might have failed but when I swap in another ecu it still does the same thing.
If it were some kind of soft rev limit it would effect two injectors and not just one.
Does anyone have any thoughts? What could possibly cause only the #4 injector to stop working after the initial start?
On the initial startup signal when the ecu tells all four injectors to shoot fuel at the same time they all work including inj #4. After that crank rotation the ecu switches to multiport port injection meaning it shoots the fuel before the intake stroke for each cylinder. At this moment is when the #4 injector stops flowing fuel.
The ecu will not allow the engine to run if it's not getting a signal from more than one failed injector. I pulled the #3 inj and the engine still started. This tells me the ecu doesn't view inj#4 as having some kind of failure.
I checked the wiring and there's no short.
I checked to see if it got 12v and they all do.
I checked the continuity from the injector to the ecu and it's within spec of the other injectors.
I also swapped the harness between #3 & #4 which causes the #3 inj to follow the same pattern. This tells me it's not the injector itself.
It's not a tipover, kickstand, neutral, safety issue because the engine does run.
I thought the ecu might have failed but when I swap in another ecu it still does the same thing.
If it were some kind of soft rev limit it would effect two injectors and not just one.
Does anyone have any thoughts? What could possibly cause only the #4 injector to stop working after the initial start?