Distributor PM

[tekenaar]

Most of us are well aware of necessary periodic PM (Preventive Maintenance) required on our venerable Bosch distributors to keep them in optimum "tune" - points (those of us that still use them), condenser (capacitor), rotor, cap. We tend to think that that's it . . . it's NOT! The single most important ignition control item is also the one that is most often overlooked or simply forgotten!

A bit of basics first. Distributors "time" the ignition point by a combination of mechanical, RPM dependent, and vacuum, load dependent, advances built into it. For these "advances" to work correctly, they must operate freely. Mechanical advance is controlled by a pair of centrifugal weights and tension springs, but for these weights and springs to do their jobs, the distributor cam assembly must rotate freely about the central distributor shaft.

That brings us to that oft forgotten item, lubricating the distributor cam assembly so that it rotates freely about the center shaft. This should be done routinely with very lightweight oil, at least once a year!

1. Remove distributor cap.
2. Turn rotor in CW direction by hand, let go and observe how freely it snaps back in CCW direction (mechanical advance springs).
3. Remove rotor and lubricate distributor shaft center felt pad with a couple of drops of light weight oil and again check freedom of movement around center shaft.
4. Replace rotor and cap and check engine timing.

[Opelkurt]

Good post- That's something I check right away when I buy an Opel; the mechanical advance is usually stuck solid, especially if the car has been sitting for some years. An easy fix and the power and fuel economy will jump.



-Kurt