In the msd manual for false triggering it says to disconnect the purple/green connection from the dist and put a jumper in between to tigger.

When I do that it fires every time I disconnect the jumper, but it also triggers the spark if I have one end of the jumper on the purple wire and touch the other end to ground. I don't need to use the green one at all.

The manual doesn't mention this possibility. Does anybody know these ignitions well and know if this is a sign of a problem?