Have you scanned for DTC'*. A malfunctioning injector will likely set a code for misfire.
I apologize if you already know this. but gettting 0 ohms resistance tells me you checked with the electrical connectors on the injector. Resistance should be around 11.4 to 12.6 ohms. You are supposed to check with a warm engine. Not hot, like when you have been driving a bit, but not cold from sitting overnight. To give you an idea, the coolant at full operating temperature is around 200*F and you want to check resistance on the injectors at around 100*F. Don't get hung up on the exact temperature, just make sure the engine isn't at full operating temperature, or cold from sitting over night.
2001 Bonneville SSEi (retired at 365,000 Kms.)
2014 Jeep Grand Cherokee Overland (yes, I know its not a GM)