[Trochoidal]

Originally Posted by L78toLT1

Hey Arpad, I spent some quality time with the Service Manual and did some more troubleshooting yesterday. Here’s what I found:


· As I mentioned earlier, all injectors have power.



· All injector signal wires have continuity from the X1 ECM connector to the injector i.e. the entire run, upstream and downstream of connector X161. I’m positive there is no signal; I validated my technique on the left bank using a noid test light. It flashed away on the left side.



· Pin number 72 on ECM connectors X2 and X3 is grounded to the back side of the driver’s side head, I believe this is G103 on the wiring diagram. Both ground paths are good. There are no other external ECM grounds.


So….I am confident that I don’t have a harness problem or a ground problem, which makes me think ECM. The only other possibility is maybe a sensor issue or sensor harness issue. While I don’t know the details, I am sure that the ECM uses the input from several sensors when firing the injectors, however I can’t envision how a sensor issue could affect only one bank. Take the cam or crankshaft position sensors for example, there are only one of each.



Unless you, or anyone else, can think of something else to check, I’m going to roll the dice on that $220 plug-and-play ECM. It will come loaded with my stock tune so I’ll have to license with HPTuners, reload my latest tune, etc. but that shouldn’t be a big deal.

I see pin 71 & 72 on X2 as unoccupied and pin 73 as ground for LT1 (2017 manual) page 11-668.

I see pin 72 on X3 as DFI High supply and pin 73 as ground for LT1 (same manual) page 11-680.

This may not be relevant to your setup, but I wanted to take a look to be a 2nd/3rd set of eyes.

Although the noid test did show no signal for pins 45-52.