Wow...I could see how that would drive you nuts. Makes no sense since the fueling/injection pulse is sensor/ecu driven. Can't even see it injector related as even if the injector was flowing too little fuel the computer would not even know that and increase the pulse unless the probes were sending feedback to tell it. Almost like it is stuck in a warmup cycle or overfueling thinking the air is colder??? Ambient temp sensor/Engine temp sensors making sense or in failsafe mode?? If I remember correctly, the pulse durations you said you saw coincide with a cold engine. Although I am sure you looked at that already. In open loop, something is driving it to the higher fueling end of the map. RPM or TPS output to the ECU are the only two factors on the map that drive that?? Although GD should display that and would look obvious. Just spitballing at this point. Are both cylinders showing the same fueling issue?