Installing and Timing a Distributor
- Disconnect the distributor wiring connector and the vacuum advance hose, if the vehicle is so equipped.
- Remove the distributor cap and note the position of the rotor. Mark the position on the distributor housing.
- On some vehicles, it may be necessary to remove the spark plug wires from the cap prior to cap removal.
- Note the position of the vacuum advance, then remove the distributor holddown bolt and clamp.
- Pull the distributor from the engine. Most distributors will need to be twisted as they are pulled out of their bore.
- Once the distributor is removed, install a shop towel in the distributor opening to keep foreign material out of the engine block.
- The entire assembly should be cleaned thoroughly. Make sure all solvent residue is completely removed.
The following procedure may be followed to install the distributor and time it to the engine, if all reference marks were made during the removal of the distributor:
- Lubricate the O-ring on the distributor shaft.
- Position the rotor so that it is aligned with the mark made on the distributor housing prior to removal.
- Align the distributor housing with the mark made on the engine block during removal.
- Lower the distributor into the engine block, making sure the distributor drive is fully seated.
- Distributors equipped with a helical drive gear will rotate at the distributor is being installed, causing the distributor to move away from the reference marks.
- Pay attention to how much the rotor moves.
- Remove the distributor and move the rotor backward the same amount. This should allow the shaft to rotate while the distributor is being installed and still be aligned with the reference marks.
- Make sure the distributor housing is fully seated against the engine block. Sometimes it may be necessary to wiggle or rock the distributor to seat it fully into the drive gear.
- Distributors with drive lugs must be mated with the drive grooves in the camshaft. Both are offset to eliminate the possibility of installing a distributor 180 degrees out of time.
The distributor must be aligned with the camshaft drive to seat the distributor in the engine block or cylinder head.
- Rotate the distributor a small amount so the timer core teeth and pick-up teeth are aligned.
- Install the distributor holddown clamp and bolt, leaving the bolt slightly loose.
- Install the spark plug wires in the direction of distributor shaft rotation and in the cylinder firing order.
- Connect the distributor wiring connectors. The vacuum advance hose is usually left disconnected until the timing is set with the engine running.
If the engine has been cranked while the distributor is removed, or no marks were made during removal, use this procedure to reinstall the distributor:
To be sure that the number one cylinder is on its compression stroke, observe the rocker arms to see that they are both moving. Then, rotate the crankshaft one revolution until the rocker arms for the companion to cylinder number one are both moving at TDC (top dead center). Align the timing mark and install the distributor with its rotor pointing to the number one spark plug cable in the distributor cap.
- Remove the spark plug from cylinder #1. Install a test plug in the end of the spark plug wire and position the test plug away from you and cylinder #1.
- Place your thumb over the bore for the spark plug and crank the engine until compression is felt.
- Lightly crank the engine while observing the timing marks on the crankshaft pulley. Once the timing marks are aligned, stop cranking.
- Identify the position for the #1 spark plug wire on the distributor cap.
- Determine which way the distributor shaft will rotate when it is lowered onto the camshaft gear. Then position the rotor so that it will be under the #1 terminal on the distributor cap after the distributor gear is meshed with the camshaft gear.
- After the distributor is installed in the engine, turn the distributor housing slightly so the pickup coil is aligned with the reluctor.
- Install the distributor holddown clamp and bolt. Hand tighten the bolt.
- Connect the pickup leads to the wiring harness.
- Install the spark plug wires onto the distributor cap according to the engine's firing order. Check to make sure everything that was disconnected before the distributor was removed, is now connected. Connect a timing light and prepare the engine for an ignition timing check and adjustment.