What are the symptoms of a bad distributor?

Answer 1

For OLDER distributors, the kind that uses points.

There aren't many moving parts on a distributor, just the center shaft, the centrifugal advance mechanism and the advance plate.

• If the advance plate is worn and not moving properly, the engine will have problems with vacuum advance and will "ping" a lot more when you step on the accelerator.
• If the centrifugal advance isn't working properly you'll either have a "kickback" when you try to start the engine, indicating that the advance weights are stuck "out", or if the weights are rusted in the IN position, you'll have a power loss.
• If the central shaft is worn it will affect the way the points open and possibly allow oil to leak into the distributor. If the points aren't opening properly it may cause the engine to completely fail, misfire or run erratically. If it's leaking oil onto the points it may not run at all.

Beyond that, you can replace vacuum advance diaphragm, points, rotor, distributor cap and condenser, all components of the distributor.

For Newer Distributors:

NEWER distributors are mostly electronic and everything is different.

The center shaft can still wear but again, that will usually mean that the engine will run poorly if at all. Personally, I haven't seen that before.

Beyond that, some of the electronic components inside the distributor can still fail but they can be replaced.