> The problem is that the Bentley only says that resistance between
>terminals 2 and 3 should "vary" as you move the airflow flap.  Well it
>varies, not smoothly, but in a seemingly random way from 0ohms (flap
>closed) up to 4000ohms if I push it in really smoothly, and back down to
>about 100ohms.
>     What should it do?

Bob,

I Worked for a general automotive repair shop, with several excellent
diagnosticians, I mainly rebuilt all types of engines. When we tested a
position sensor, we would use a analog ohmmeter and if the needle hesitated
in ANY way (I mean we did our best to slooowwwly cycle it) at all when
cycling the sensor, either going up or coming down, the sensor was bad and
a new one cured the problem. Check the new one also, I've seen them with a
glitch outta the box too!  Our sensors were mainly throttle position
sensors, so I can't absolutely vouch for an air flap sensor,  but yours
should smooothly increase and decrease resistance throughout its scale.
BTW, these sensors, from my exposure at the shop, were one of the first
things checked when a drivability problem was the complaint-- Stalls,
hesitation, rough running etc.

Mark Keller
91' Carat project