if i remember correctly from one of martins other posts on forums, the Throttle pos switch advances the timming to 35 deg, so on tickover you have 17deg the slight touch of the throttle it goes to 35deg.
correct me if im wrong
im also still looking for an s12 "bible" on CD if anyone that has one wants to copy it for me
ta
i just got one for my stepdads terrano, its fooking brill!!!!!