Still the same problem : up to 3500 rpm when the distribitor reaches maximum advance no problem, from there on the the timing mark starts jumping around between 30 to 40 degrees. Timing is set to 18º initial and 38º max.
I replaced the 6AL box with a new one
and still the same problem. I had the cable going from the box to the magnetic pickup in the distributor routed behind the firewall and along the left fender. The wire is also shielded and both shield ends are grounded.
I do not know if it can be the pickup, but I have read that these units either work or don't. Before ordering a new pickup I would like to know if that has caused problems for someone else. I do not know what else can cause this
.
Thanks for your help.