<VV> High Idle - 1966 Corsa 140

[faith bennetts]

Hi Guys,
 Help!!!! I am befuddled. I have a 1966 Corsa 140 and can't get my idle below 950 rpm. I have disconnected the secondaries and capped them. I have disconnected the linkage on both primaries from the accelerator rod and each other to isolate them and it still idles high even with the idle screws completely off the idle tang. The only way I can get a lower idle speed, 600-650 rpm, is to retard the timing about 10 deg. I have a Pertronics II. Would this be affecting the timing? Do I have to back the timing off from the book setting of 18 deg BTDC? Are there any other things that I can try to get the idle down? 
 
Thanks in advance for your replies.
 
 
Jim Bennetts 1966 Corsa vert. 140 4-spd
Akrom, OH