The distributor is bevel gear driven by the camshaft on 1973-83 engines except Prelude. On the 1983 Prelude the distributor is driven directly by the camshaft.
All distributors utilize centrifugal advance mechanisms to advance ignition timing as engine speed increases. Centrifugal advance is controlled by a pair of weights located under the breaker plate. As the distributor shaft spins faster, the weights are affected by centrifugal force and move away from the shaft, advancing the timing.
In addition, all distributors use some kind of vacuum ignition control, although this varies from model to model.
Vacuum advance works as follows: When the engine is operating under low load conditions (light acceleration), the vacuum diaphragm moves the breaker plate in the opposite direction of distributor rotation, thereby advancing the timing.
Vacuum retard, on the other hand, is actuated when the engine is operating under high vacuum conditions (deceleration or idle), and moves the breaker plate in the same direction of rotation as the distributor, thereby retarding the spark. On models equipped with both vacuum advance and retard, both these ignition characteristics are true. You can always tell a dual diaphragm distributor by its two hoses.
REMOVAL & INSTALLATION
Breaker Point Type
See Figures 1, 2 and 3
- Disconnect the negative battery terminal from the battery.
- Disconnect the high tension (distributor-to-coil) lead and the primary leads, then, move them out of the way.
- At the distributor cap, unsnap the retaining clamps. Remove the distributor cap and move it out of the way.
To position the No. 1 piston at the TDC of its compression stroke, perform the following procedures:
- Locate the No. 1 spark plug wire position on the distributor cap and align the cap with the housing.
- Using a piece of chalk, mark the No. 1 cylinder position on the distributor housing.
- Using a wrench on the crankshaft pulley, rotate the crankshaft until the distributor rotor aligns with the mark on the distributor housing.
- Using a piece of chalk, mark distributor rotor-to-housing position and the distributor housing-to-engine position. When this is done, the mark on the distributor housing should be aligned with the rotor tip and the engine block mark.
This aligning procedure is very important because the distributor must be reinstalled in the exact location from which it was removed, if correct ignition timing is to be maintained.
- Note the position of the vacuum line(s) on the vacuum diaphragm with masking tape, then, disconnect the line(s) from the vacuum unit.
- Remove the distributor holddown bolts and the distributor from the engine.
- To install, place the rotor on the distributor shaft and align the tip of the rotor with the line that you made on the distributor housing.
- With the rotor and housing aligned, insert the distributor into the engine while aligning the mark on the housing with the mark on the block or extension housing.
Since the distributor pinion gear has helical teeth, the rotor will turn slightly as the distributor gear meshes with the camshaft gear. Allow for this when installing the distributor by aligning the mark on the distributor with the mark on the block but positioning the tip of the rotor slightly to the side of the mark on the distributor.
- When the distributor is fully seated in the engine, install and tighten the distributor holddown bolts.
- To complete the installation, reverse the removal procedures. If necessary, refer to Engine Performance and Tune-up to check and/or adjust the ignition timing.
If the engine was cranked with the distributor removed, it will be necessary to retime the engine. If you have installed the distributor incorrectly and you have found that, for that reason, the engine will not start, remove the distributor from the engine and start from scratch.
To position the engine on the correct firing position, perform the following procedures:
- Remove the No. 1 spark plug from the engine.
- Using a clean rag, insert it into the spark plug hole.
- Using a wrench on the crankshaft pulley bolt, rotate the engine until the compression blows the rag from the No. 1 cylinder. Check and/or align the engine's timing mark(s); this is the TDC of the No. 1 cylinder's compression stroke.
- Align the rotor with the No. 1 cylinder position on the distributor housing.
- Carefully insert the distributor into the cylinder head opening with the holddown bolt slot aligned with the distributor mounting hole in the cylinder head, then, secure the plate at the center of the adjusting slot. The rotor head must face No. 1 cylinder.
Since the distributor pinion gear has helical teeth, the rotor will turn slightly as the gear on the distributor meshes with the gear on the camshaft. Allow for this when installing the distributor by positioning the tip of the rotor to the side of the protrusion.
- To complete the installation, reverse the removal procedures. If necessary, refer to Engine Performance and Tune-up to check and/or adjust the ignition timing. Inspect and adjust the point gap.
See Figures 4 and 5
- Using masking tape, remove the spark plug wires from the cap and number them for installation as they are removed.
- Disconnect the vacuum hoses, the primary wire and the high tension wire.
- Remove the holddown bolt(s) and pull the distributor from the head.
- Crank the engine until No. 1 piston is at TDC of its compression stroke.
- Using a new O-ring, install it on the distributor housing.
- Align the raised mark on the lower part of the distributor housing with the punch mark on the distributor gear shaft. Insert the distributor into the head and the rotor will turn to No. 1 firing position. Loosely install the holddown bolt(s). Tighten the bolt(s) temporarily and replace the cap.
- Connect all wires and hoses.
- Start the engine and adjust the ignition timing.