Tools You'll Need:
* Timing light: This is essential for accurately setting the timing.
* Socket wrench and sockets: To access the distributor.
* Distributor wrench: To rotate the distributor.
* Owner's manual or repair manual: Provides the proper timing specification for your specific engine. This is crucial.
* Spark plug wrench: To remove a spark plug (optional, but helpful for checking cylinder #1)
* A helper (optional but recommended): One person to monitor the timing light while the other adjusts the distributor.
Procedure:
1. Safety First: Disconnect the negative (-) battery cable before starting any work on the ignition system.
2. Locate Timing Marks: Find the timing marks on the harmonic balancer (the pulley at the front of the engine) and the timing pointer on the engine block. These markings are crucial for setting the timing accurately. Clean them if necessary.
3. Find Top Dead Center (TDC) on Cylinder #1: This is the most important step. With the distributor disconnected, crank the engine (carefully by hand using a wrench on the crankshaft or by slowly turning the engine over with the starter) until the timing mark on the balancer aligns with the 0° mark on the timing pointer. Verify that you are on the compression stroke (both valves closed) for Cylinder #1. This usually requires removing a spark plug on Cylinder #1 and using your finger (carefully!) or a piston stop tool to check piston movement. Getting this wrong will lead to an incorrectly set timing.
4. Connect the Timing Light: Connect the timing light according to the manufacturer's instructions. Usually, you'll clamp the light to a spark plug wire (often the number 1 cylinder). The light's sensor will need to be connected to the battery.
5. Start the Engine: Have your helper crank the engine while you observe the timing light shining on the timing marks. The timing light will flash, illuminating the timing mark on the balancer.
6. Read the Current Timing: Note the timing mark position displayed by the timing light. This is your engine's current timing.
7. Adjust the Distributor: Loosen the distributor hold-down clamp (usually a bolt or two). Using the distributor wrench, carefully rotate the distributor slightly clockwise or counter-clockwise to adjust the timing. Each degree of rotation will significantly impact the engine. Small adjustments are essential, and you should observe the timing light after each adjustment.
8. Set the Timing: Using the specification from your owner's manual (this is VERY important – the timing specification can vary quite a lot depending on the model), rotate the distributor until the timing light shows the correct advance. This is usually specified at idle and in certain engine RPMs. Your manual will tell you the ideal setting at idle (with the vacuum advance disconnected) and potentially further advance as RPM increases.
9. Reconnect the Vacuum Advance (if applicable): Your engine likely uses a vacuum advance on the distributor, re-connect this once the base timing is set.
10. Tighten the Distributor Clamp: Once the timing is set correctly, tighten the distributor hold-down clamp securely.
11. Reconnect the Battery Cable: Reconnect the negative (-) battery cable.
12. Test Drive: Test drive the vehicle to ensure the timing is correct. The engine should run smoothly and efficiently. If not, re-check your work, particularly the TDC alignment in step 3.
Important Considerations:
* Vacuum Advance: The vacuum advance mechanism on the distributor adds timing as engine vacuum increases (during lighter loads). You usually set the initial timing with this disconnected, then reconnect it after setting the base timing.
* Mechanical Advance: There's also a mechanical advance mechanism inside the distributor. This is usually not adjustable and contributes to the overall timing advance as engine speed increases.
* Professional Assistance: If you're uncomfortable working on your engine, take it to a qualified mechanic. Incorrectly setting the timing can damage your engine.
Remember, this is a general guide. Always refer to your vehicle's repair manual for the precise procedure and timing specifications. The repair manual will provide the specifics for your 1982 350 Chevy, including any nuances based on its exact configuration and optional equipment.
