Ron,
If you suspect distributor wear (and even if you don't), consider installing a Pertronix 1885 in place of the points. It is not sensitive to distr shaft wobble and eliminates ever having to set points or measure dwell again! Cost is under $100. No need to do anything more than take the points out, slip the Pertronix in and attach two wires down near resistors.
I have a write up on how to adjust the MPS, but you have to have a
GOOD CO meter or a wide band AFR meter before you start. Don't bother with one of those old wheatstone bridge type units. A Gunson or a pro type 5-gas meter is needed, or an AFR meter like the ones I referred you to earlier.
In the meantime, have you pulled your plugs? They can tell you a lot about the way your engine is tuned.
This document shows my plugs during a time when my trigger points were worn. To check the trigger points, you need to remove the distributor, then connect a meter to common and then to each other contact in turn. While rotating the rotor by hand, note the angle that each of the 4 contacts closes for. It should be something in the 100deg range. In my case one was barely closing, but showed up as OK using the MB test.
Typical plug after correcting trigger point problem.
Finally, an easy job - locate the ground connection on top/rear of engine where the injection system is grounded - clean this connection as well as the chassis ground near the battery. These can cause intermittent faults.
Aren't these old D-Jets fun
