Thank's for Jim Lill and Francisco responses.
FYI, I've measured it using needle type ohmmeter and it showed around 50 ohm
at fully closed flap (pointer is at most right position). When pushing the
pointer to the left turn slowly the ohmmeter increases normally, but at
certain angle (around 20-30 degrees) the ohmmeter indicates almost infinite
and when continuously push the pointer to the left turn slowly the ohmmeter
indicates around 200 ohm (I think it's normal) and when the pointer is at
around 60 degrees of angle the ohmmeter indicates almost infinite again and
after that the ohmmeter indicates normal until around 1000 ohm at 180
degrees of angle (most left position).
After this measurement I plug the connector and run the engine with the
black rectangular cover of AFM is still open, and push the throttle slowly
until the AFM pointer turns at around 20-30 degrees of angle (it is around
1300 RPM) and the problem occurs, the ZDJL's rpm is unstable (going up and
down).
Is it possible that the surface of the resistor which is pointed by the
pointer was scraped since my ZDJL was 10 years old ?
I've read this address
http://triumph.cs.utah.edu/TR8/Digests/FuelInj/TR7AFM.html , I hope my AFM
has the same schematic except the resistors value.
I'll check again this week end.
Merry Christmas for you all.
Bambang Himawanto
'89 505 GTI (ZDJL)
Bandung - Indonesia