Cat 3406e wont come off idle rpm

Have a cat 3406e with 2WS00628 serial number.

First a little history;

Driver says last couple months the engine would run a bit rough at idle, over time it got progressively worse.
Fast forward to now, we pressure washed whole truck thouroughly and parked it. Restarted truck to pill in shop for service. Once in shop truck would crank but not start.

Found blown ECMs fuse, changed fuse and truck would start (fuse has not blown since) but ran rough (as if not firing properly on all 6) and will not come off idle rpm regardless of throttle pedal position. According to tach its running about 550 rpm.

I dont know if my issues are from water from pressure washing or its just a coincidence.

I got flash codes 72,73,74 for the injectors. All 6 injectors show a injector current fault. Im using a pro link iq scanner, dont have cat et scanner.

I have communication from data port to scanner, also when i push throttle pedal scanner shows the throttle position percentage seems to be working fine (as i push pedal throttle percentage will increase and decrease as it should.

I checked both J1 and J2 connectors, unplugged them from ECM and all pins look good and corrosion free. Got keyed power on pin 70 and battery power on the other 2 respective pins as per service manual, Got ground on 2 respective pins as per service manual also.

Tested harness from J2 to injector harness pass thru plug for open circuit or short and it test good.

I know it may be premature to pinpoint problem with what i looked into so far but any ides where to go next?

Im no electronic expert, learning as i go.

What has me stumped is it will not come off idle regardless of throttle position. My experience is with injector current faults engine will still rev up but run rough or clear up a bit. Not getting any smoke out exhaust (looks clean)

Could bad injectors prevent it from running above idle?
Or bad ECM cause it to not come off idle?

Ive never come across this type of problem any help would be appreciated,

 

I tried using cruise to rev up to no avail and scanner is saying that cruise set and resume switches are functioning

Pass thru plug appears ok, haven’t checked injectors harness yet.

I wiggles wires at j1-j2 and pass thru connectors, no change

Maybe I’ll check fuel pressure and injectors harness next.

I haven’t load tested any wires for Ecm power and ground, just used a test light, never saw any ecm voltage codes and scanner saying 13.8 volts at ecm while its running

Same goes for j2 to pass they harness

What do you guys use for load test? I’ve used a led light before to load test ecm power and ground, not sure if this is sufficient way to load test. Aren’t signal wires to injectors 120volt?