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Hi there, I am Cam. Can I ask if you had the orientation of the engine correct? On the druramax, Drivers side is even, 2-4-6-8 and passengers side os odd, 1-3-5-7. Is this what you expected and did you change all or just the effected ones?
OK, when you say the top harness and pigtails, you mean the top engine harness and the pigtails that go to the injectors under the valve covers?
This only starter after replacing the injectors or did this start before replacing the injectors?
Ok, so to make sure I understand completely, you replaced the injectors, this started, you replaced the rest and it remained?
Ok, so one of the injectors, 2 3 5 or 8 is causing this. It has a fault inside and when it, the FICM detects one injector out or spec, it disables the group of injectors, in this case, 2 3 5 and 8. Unless it shows you a P020(2,3,5,8), its going to take testing each injector when the issue happens to know which to replace.
Understood. IF all of these were the EXACT same resistance, and you were using a quality meter with the leads zeroed out, then you would have to do what I would, pick a bank, replace the 2 and see which is does. Beyond what you have done, there is nothing special about testing these. They run on 93 volts from the FICM so we cannot simply apply voltage to see. I know this is not what you want, but the fact of the matter is that your diagnosis is spot on so far.
Were these GM injectors or aftermarket injectors?
Exactly what resistance did you get for each injector?
And that is right in the middle of the spec. IT is 0.3 to 0.8 ohms. Did you zero the meter before testing?
Ok, self zeros, that must be a good one. Sorry no. The FICM is not that advanced. It works in groups. While it controls each injector individually, if one goes out of spec, it disables the group. Attached is the diagnostic chart for this.
Unfortunately, yes. WE know its one of four, so myself I would Contact the supplier and explain to them what is happening. Then replace 2 as the time to get under each valve cover makes it harder to justify going in twice, unless you happen to get the bad injector straight away. However, I would get this engine really hot then test each injector again to see if you still only get 0.5 ohms.
I think that is enough of a reason to replace it. Getting an inconsistent reading and one that does drop below spec points to it as being faulty. Replace that injector.
The short and the wiring does not pass through those 2 large connectors, rather it goes straight from the FICM to the injectors. Everything you tested and the codes suggest it's a bad #2 injector.