Update for
@muc @tpenfield @alldodge
I replaced the Knock Sensor #2 and it was in rough shape, just took the boat out and for 4 minutes straight ran it between 3000-4000 RPM with no alarms. Attaching the Diacom log for it. Do you see improvements from replacing the Knock Sensor #2? I want to take it out later for a longer ride, but wanted to at least test it out. The acceleration starts right after the 4 minute mark
drive.google.com
Yes I see a vast improvement. If you look at the KS voltage they are now very close to each other. Before KS 2 was much lower than KS1.
I’m pretty sure the soft warning was due to KS 2 voltage falling below 0.1 volts. This was latching and unlatching so fast it didn’t meet the requirements to set a code but did set a soft warning. Kind of a glitch in the program. This is one that would have been much harder to diagnose with a techmate, But not too bad with Diacom.
On this engine, knock retard will not set a code or warning. It’s actually normal to see on a properly functioning engine. What happens with this type of engine is the spark advance is always hunting around (once the correct parameters have been met) to find the best possible power/efficiency. This is one of the reasons why EFI engines will always beat carb engines. It gets even better once O2 sensors are added because then fuel adjustments can be fine tuned.
@apisk I see octane rating is now a little higher. Did you add fuel between these last 2 recordings? I don’t have a really great grasp on how exactly this works, so always trying to learn when I see these changes.
Well congratulations, it looks like you got this one sorted out. Thanks for letting me help.