Darcy---It doesn't sound like a carb problem to me, especially after
going to another setup and the stumble or misfire is still there. Nor
should the vacuum retard make any difference, keeping in mind that it
should only retard at idle, not at the rpms that you reported.
Check the points and the wiring to and from them. Use a jumper wire to
go from another 12V source to the coil + side, at least long enough to
test the car again for this misfire.
Again, it should make no difference to the misfire solution, but there's
20 deg. of advance built into the centrifugal mechanism in your
distributor. If you set it at 12 BTDC at idle, when no advance is taking
place, you should be seeing 32 deg. at 3500 rpms, unless someone has
altered the curve.
Dick Taylor
|