Does OBDI ECM "learn" a fuel map?

[nosigma]

I see a lot of posts commenting on the ECM needing time to learn a fuel map. I thought that the fuel map was programmed (burned) in and not learned.

Does the OBDI system learn a new fuel map?
Does the OBDII system learn a new fuel map?

If the OBDI system does in fact learn a new fuel map is it lost once the battery is disconnected?
If the OBDII system does in fact learn a new fuel map is it lost once the battery is disconnected?

John

[nosigma]

Through extensive searching I found one post where an OBDI owner hooked up to a Chryser DRB scanner and he reported

"I was surprised to see that OBD1 holds both short- and long- term adaptive fuel values so OBD1 does adjust to some degree to cope with permanent rich or lean conditions, plus probably adapting to the driver's style. I didn't think it had that level of smarts"

While this is a far cry from the computer learning the motor set up and adjusting to it, it does suggest that the computer makes some on the fly adjustments and retains them for some length of time.

John