Gentlemen,
As I had mentioned in a previous post, there is nothing wrong with the MP distributor in theory. The reluctor, is nothing more than a rotating magnet. The "teeth" or spikes when they rotate past the pick up coil assembly, generate a voltage in the pick up coil which is fed to the control box, be it any color (orange or gold), which is amplified and used to turn OFF the ignition coil's primary voltage via the transistor on the control box, which causes the ignition coil to generate the approximately 30,000 volts sent to the plugs. The reluctor may be the cause of the difficulties. The teeth on the reluctor must be sharp to generate the pulse of the correct "shape" that the control box can process. The reluctor has 2 directional arrows to show the leading edge and MUST be installed in the direction that the distributor rotates. Sometimes the MP vacuum advance will cause the pick up coil to move eccentrically (not in the same centerline as the shaft) that will cause the reluctor to pick up coil air gap to change resulting in"spark scatter" and erratic operation. The fix?..... make sure the reluctor gap is correct (usually 0.006" to 0.008") the closer the better as it helps generate the correct pulse. Consider NOT using the vacuum advance and recurve the mechanical advance to bring the RATE of advance faster......all advance by say 35 degrees all in by 2200 RPM, but this must be determined by the owner.
Petronix is good but everything is self contained. One should consider keeping a spare module in the car....just in case.....you are not likely to find a replacement at an autoparts store.
I still use an numbers matching Prestolite dual point distributor with Mopar points....which I can buzz up to 6800 RPM without any missfire or point bounce......I still prefer the old way vs the MSD or Petronix method. Once the plugs ignite the fuel mix, how much voltage the system generates does not really matter, the ignition system's job is done.
This is just my opinion....
Cheers,
RJ RENTON
