At 12:03 AM 12/5/2009, Arkady Mirvis wrote:
>What is idle stub system? Ark

Sorry Ark -- the full name is idle stabilization system.  On the 1.9l
engines it's an electrical box plugged into the output from the
Hall-effect sensor in the distributor, and it alters the timing to
keep idle speed constant.

On the 2.1l it's a much fancier box of electrical tricks located
forward of the right tail-light, which constantly adjusts and
electrically operated air valve, like an auxiliary throttle, that
throttles up the engine to compensate for idling loads.  I presume
that the second system is more fuel-efficient, as the earlier system
functioned quite well.  Or it may have been that the addition of
power steering and A/C made it simpler to go to a unified system.

Yours,
David