Distributor: Description and Operation

Distributor Showing Rotor Lined Up With Reference Mark On Distributor Housing:

Typical Hall Effect Distributor Assembly:

The V8 engine uses two distributors, one on the rear of each cylinder head. They are driven by the camshafts in the heads and rotate at the same rate as the cams (1/2 the rpm of the crankshaft). Only one distributor (the one on the right side cyl. head) contains a hall sensor for an ignition reference signal. The other contains just a rotor and cap to distribute the spark to its four respective cylinders. Each distributor is installed in a position so that as it's turning and a spark is generated by its ignition coil, the rotor is always pointing at the appropriate terminal of the cap to direct the spark energy to the correct cylinder.
Although the actual ignition timing is controlled by the ECM, it is important that the distributor installed position is correct (especially the right side distributor), since the hall sensor provides the reference signal from which the ECM calculates crankshaft position (relative to TDC of cyl. #1) during initial start-up.