Hey gang, question on how the ECM handles Idle on my 886. Yester day I was headed out for a drive, fired up the engine and it just died, tried a few times it just died. If I hit the gas pedal, it fired up, ran fine, until I let off the gas. i popped the hood and noticed my PVC valve was almost out of the valve cover and the vent came loose on the other valve cover. My guess is I yanked on those lines at some point when I was under the hood doing other things, didn't even notice. So, I plugged everything back in and went to start the car. Still wouldn't stay running. I eventually started it and just let it run for a while, maybe 4 or 5 minutes, then it was fine. has been idling perfectly ever since.

so here's the question.

Does the ECM "learn" idle as conditions change? So, if my PVC valv was working its way loose, crating a vac leak little by little and messing up the crank case pressure I guess, does the ecm work through tables like today's ECMs, eventually getting to the end and quitting? then, when I fixed the problem, did it have to relearn the environment, which is why it took a while to get my idle back?

Hope that made sense, just want to understand what all happened. My dodge Ram is like this, but worse. If I disconnect the batter on my dodge, the damn truck has to relearn idle all over again.

Thanks much.

bob

 

When the engine is cold it runs on tables in the ECM. There is no learning involved. The learning doesn't happen until the ECM goes into closed loop mode.

 

Yeah. That makes sense. Thanks much.