Ignition Distributor Advance Mechanism Sticking: A Comprehensive DIY Guide

Ignition distributor advance mechanism sticking is a common issue that can significantly impact the performance and efficiency of an internal combustion engine. The ignition distributor advance mechanism is responsible for advancing the ignition timing as the engine speed increases, which helps to optimize combustion and improve fuel efficiency. However, if the advance mechanism sticks, it can lead to a variety of problems, including reduced power, increased fuel consumption, and increased emissions.

Understanding the Ignition Distributor Advance Mechanism

The ignition distributor advance mechanism is a critical component of the ignition system, and its proper functioning is essential for the engine’s optimal performance. There are several key measurements and specifications that are important to understand when diagnosing and addressing ignition distributor advance mechanism sticking:

Advance Curve

The advance curve is a graph that shows the relationship between engine speed and ignition timing. It is typically measured in degrees of crankshaft rotation and is specific to each engine and application. The advance curve can be affected by a variety of factors, including the design of the engine, the type of fuel being used, and the operating conditions. For example, a typical advance curve for a gasoline engine might show the ignition timing advancing from 10 degrees before top dead center (BTDC) at idle to 35 degrees BTDC at high engine speeds.

Advance Mechanism Type

There are several types of advance mechanisms used in ignition distributors, including vacuum-operated, centrifugal, and mechanical. Each type has its own specific design and operating characteristics, which can affect its susceptibility to sticking. For instance, vacuum-operated advance mechanisms are more sensitive to changes in engine vacuum, while centrifugal advance mechanisms rely on the engine’s rotational speed to advance the ignition timing.

Advance Mechanism Clearance

The clearance between the advance mechanism and the distributor body is a critical measurement that can affect the performance and durability of the ignition system. If the clearance is too tight, it can cause the advance mechanism to stick, while if it is too loose, it can cause excessive wear and noise. The recommended clearance for a typical ignition distributor advance mechanism is typically between 0.010 and 0.020 inches (0.25 to 0.50 mm).

Advance Mechanism Travel

The travel of the advance mechanism is another important measurement that can affect ignition timing. This is the distance that the advance mechanism moves as it advances the ignition timing. If the travel is restricted or obstructed, it can cause the advance mechanism to stick. The typical travel for a centrifugal advance mechanism might be around 20 to 30 degrees of crankshaft rotation.

Advance Mechanism Lubrication

Proper lubrication of the advance mechanism is essential to prevent sticking and ensure smooth operation. This typically involves using a high-quality lubricant, such as a silicone-based grease, and ensuring that it is applied to all moving parts of the advance mechanism. Inadequate lubrication can lead to increased friction and wear, which can ultimately cause the advance mechanism to stick.

Diagnosing and Addressing Ignition Distributor Advance Mechanism Sticking

ignition distributor advance mechanism sticking

If you suspect that your ignition distributor advance mechanism is sticking, there are several DIY techniques that you can use to diagnose and address the issue:

Cleaning the Advance Mechanism

The first step in addressing ignition distributor advance mechanism sticking is to disassemble the distributor and clean the advance mechanism. This can be done using a suitable solvent or cleaning agent, such as carburetor cleaner or brake cleaner. Be sure to thoroughly clean all moving parts and remove any dirt, debris, or deposits that may be causing the advance mechanism to stick.

Adjusting the Advance Mechanism Clearance

If the clearance between the advance mechanism and the distributor body is too tight, it can cause the advance mechanism to stick. To address this, you can adjust the clearance to the recommended specification using a feeler gauge. This may involve loosening the advance mechanism mounting screws and adjusting the position of the mechanism within the distributor body.

Lubricating the Advance Mechanism

Proper lubrication of the advance mechanism is essential to prevent sticking and ensure smooth operation. This can be done by applying a high-quality lubricant, such as a silicone-based grease, to all moving parts of the advance mechanism. Be sure to follow the manufacturer’s recommendations for the type and amount of lubricant to use.

Replacing the Advance Mechanism

If the advance mechanism is worn or damaged, it may need to be replaced. This involves disassembling the distributor and installing a new advance mechanism that meets the specifications of the engine and application. When replacing the advance mechanism, be sure to follow the manufacturer’s instructions and use the correct replacement parts.

Conclusion

Ignition distributor advance mechanism sticking is a common issue that can significantly impact the performance and efficiency of an internal combustion engine. By understanding the technical specifications and quantifiable data associated with the advance mechanism, and using DIY techniques such as cleaning, adjusting, lubricating, and replacing the mechanism, you can effectively diagnose and address this issue.

References

  1. Rules for Air Quality Control
  2. Air Quality Control – GA – GAC
  3. Pharmaceutical Manufacturing Handbook
  4. A Hermeneutic Study of Industrial Distribution