Ford 655A Injection Pump Timing

[MikePhua]

The Ford 655A is a well-known backhoe loader that has seen widespread use in construction, landscaping, and agricultural applications. Like many older machines, the Ford 655A is powered by a diesel engine that relies on an injection pump to deliver fuel to the engine at the correct timing. Proper injection pump timing is critical for engine performance, fuel efficiency, and longevity. This article will explore the importance of injection pump timing for the Ford 655A, the potential issues that arise from incorrect timing, and how to correctly adjust and maintain the timing for optimal performance.
Overview of the Ford 655A
The Ford 655A was introduced in the 1970s as part of Ford’s backhoe loader series. With a powerful diesel engine and hydraulic systems, the 655A became a popular choice for construction and digging tasks. The machine’s ability to perform a wide range of tasks—ranging from digging trenches to lifting and carrying materials—made it a versatile tool on job sites.
The 655A's diesel engine is equipped with a mechanical fuel injection system, which is controlled by an injection pump. This pump plays a crucial role in ensuring that the engine receives the correct amount of fuel at the right time. If the pump’s timing is off, the engine may experience a loss of power, excessive fuel consumption, and increased wear and tear, ultimately affecting the overall performance of the machine.
The Role of the Injection Pump in the Ford 655A
The injection pump is responsible for delivering fuel into the engine cylinders at precisely the right moment in the combustion cycle. In diesel engines like the one in the Ford 655A, fuel must be injected at the optimal time to achieve efficient combustion. If the timing is too early or too late, it can result in a variety of performance issues, such as rough idling, poor acceleration, or even engine damage in severe cases.
Proper injection pump timing ensures the following:

1. Efficient Combustion: Proper timing allows for optimal fuel-air mixture and complete combustion, improving fuel efficiency.
   
2. Power Delivery: Accurate timing ensures that fuel is injected at the right time to maximize power output.
   
3. Reduced Emissions: Correct timing can help reduce the emission of harmful exhaust gases.
   
4. Engine Longevity: Properly timed injection minimizes wear and tear on the engine, extending its lifespan.
   

Symptoms of Incorrect Injection Pump Timing
If the injection pump on the Ford 655A is out of timing, several performance issues can occur. Common symptoms include:

1. Hard Starting: The engine may be difficult to start, particularly in cold weather, because the fuel is injected at the wrong time, preventing proper ignition.
   
2. Rough Idling: If the fuel is injected too early or too late, the engine may idle roughly or inconsistently.
   
3. Excessive Smoke: Incorrect timing can result in incomplete combustion, leading to the production of excessive black or white smoke from the exhaust.
   
4. Power Loss: A noticeable loss of power during operation is a common sign that the injection timing is incorrect. This can also result in poor acceleration or sluggish performance.
   
5. Increased Fuel Consumption: When the injection timing is incorrect, the engine may burn more fuel than necessary to perform the same work, reducing fuel efficiency.
   
6. Engine Knock or Pinging: If the timing is too advanced, the fuel may ignite prematurely, causing an audible knocking or pinging sound from the engine.
   

How to Set Injection Pump Timing on the Ford 655A
Setting the injection pump timing on the Ford 655A requires a few critical steps. Although the process can be complex and requires technical expertise, it is important for maintaining the performance of the machine. Below is an overview of the procedure:

1. Preparation:
   • Ensure the engine is off, and the machine is on a level surface.
     
   • Disconnect the battery to prevent accidental starting.
     
   • Remove any necessary panels or covers to access the injection pump.
     
2. Align the Timing Marks:
   • The injection pump is typically equipped with timing marks that must align with specific marks on the engine. These marks are used to set the correct timing for the fuel injection.
     
   • Rotate the engine by hand (using a wrench on the crankshaft pulley) to align the timing marks on the pump and the engine.
     
3. Loosen the Injection Pump:
   • The injection pump may be bolted to the engine with a series of fasteners. Loosen these bolts just enough to allow the pump to be rotated slightly.
     
4. Check the Timing with a Dial Indicator or Timing Light:
   • Depending on the specific model and system, a dial indicator or timing light may be required to check the exact timing of the fuel injection. These tools will measure the timing of when the fuel is injected into the cylinder.
     
   • For a Ford 655A, the specific timing setting is typically given in the engine service manual (often around 15° before top dead center for older Ford diesel engines, but this can vary by model).
     
5. Adjust the Injection Pump:
   • If the timing is off, rotate the injection pump carefully while watching the timing marks. Adjust until the marks align with the correct timing specification.
     
   • Tighten the injection pump bolts once the correct timing is set.
     
6. Reassemble and Test:
   • Reassemble any parts that were removed to access the injection pump, such as covers or panels.
     
   • Reconnect the battery, start the engine, and test the operation. Monitor the engine for any signs of rough idling, smoke, or poor performance.
     
7. Final Verification:
   • If available, use diagnostic equipment to verify that the injection timing is correct and that the engine is operating as expected.
     

Common Challenges and Solutions

1. Sticking or Seizing Injection Pump:
   If the injection pump is seized or sticking, it may be difficult to adjust the timing. In such cases, the pump may need to be cleaned, repaired, or replaced. Regular maintenance of the injection system can help avoid these issues.
   
2. Incorrect Timing Mark Alignment:
   In some cases, timing marks on the injection pump or engine may have worn or become misaligned. Using a timing light or dial indicator can help you find the correct alignment, even if the marks are not visible.
   
3. Faulty Timing Components:
   The injection pump’s components (such as the timing gears, camshaft, or governor) may wear out over time, causing the timing to drift. Regular inspection and replacement of worn parts can help maintain proper injection timing.
   

Preventive Maintenance for the Injection Pump
To keep the injection pump operating at peak performance, consider the following maintenance practices:

1. Regular Fuel Filter Changes:
   Keeping the fuel system clean is essential for the health of the injection pump. Replace fuel filters regularly to prevent debris from entering the pump and causing damage.
   
2. Use Quality Fuel:
   Low-quality fuel or fuel with high water content can cause damage to the injection system. Always use clean, high-quality diesel fuel that meets the manufacturer's specifications.
   
3. Regular Inspection:
   Periodically check the condition of the injection pump, fuel lines, and related components. Look for signs of wear, leaks, or contamination that could affect the timing or performance of the pump.
   

Conclusion
Proper injection pump timing is crucial for maintaining the performance, efficiency, and longevity of the Ford 655A backhoe loader. Incorrect timing can lead to a variety of operational issues, including hard starting, rough idling, excessive smoke, and power loss. By regularly checking and adjusting the injection pump timing, you can ensure that your 655A runs smoothly and efficiently for years to come. Always follow the manufacturer’s specifications, and if necessary, seek the help of a professional technician to perform adjustments. With proper maintenance, your Ford 655A will continue to serve as a reliable and versatile machine on the job site.