Detailed Guide to Timing the Injection Pump on the 1979 Ford A-62 268CID Turbo Diesel Engine

[MikePhua]

Introduction to the 1979 Ford A-62 268CID Turbo Engine
The 1979 Ford A-62 268 cubic inch displacement (CID) turbocharged diesel engine is a robust powerplant widely used in heavy-duty trucks and industrial applications during its era. Its injection pump timing plays a critical role in engine performance, fuel efficiency, and emissions control. Properly setting the injection pump timing ensures optimal combustion, power delivery, and longevity.
Understanding Injection Pump Timing
Injection pump timing refers to the precise point during the engine’s combustion cycle when fuel is delivered to the cylinders. It is critical because:

• Early timing can cause engine knocking, excessive exhaust smoke, and overheating.
  
• Late timing leads to reduced power, poor fuel economy, and increased emissions.
  
• Accurate timing balances performance and engine wear.
  

Technical Terminology

• Injection pump: A mechanical or electronic device that pressurizes and delivers fuel to the engine’s injectors.
  
• Timing marks: Visual indicators on the engine components used to align the injection pump and crankshaft.
  
• Top dead center (TDC): The position of the piston at the highest point in its cylinder.
  
• Camshaft and crankshaft alignment: Synchronization of these shafts to ensure correct valve and fuel timing.
  
• Fuel advance: The lead angle before TDC when fuel injection begins.
  

Steps to Set Injection Pump Timing

• Remove necessary engine components to access the injection pump and timing marks.
  
• Rotate the engine to top dead center on cylinder number one compression stroke.
  
• Align crankshaft timing marks with the designated TDC indicators on the engine block.
  
• Adjust the injection pump position so that its timing marks align with corresponding reference points.
  
• Tighten the pump mounting bolts carefully while maintaining alignment.
  
• Double-check timing marks after tightening to ensure no shift occurred.
  
• Reassemble any removed components and start the engine to verify smooth running and proper timing.
  
• Use a timing light or diagnostic tool if available to fine-tune the timing under running conditions.
  

Common Challenges and Tips

• Timing marks may be worn or obscured by dirt and grease; cleaning them improves accuracy.
  
• The injection pump may have a degree of free play; securing it firmly prevents timing drift.
  
• Using factory service manuals with exact timing specifications avoids guesswork.
  
• Some models require setting the fuel advance via a screw or mechanism on the pump.
  
• Double-checking timing after engine warm-up accounts for thermal expansion effects.
  

Operator Stories and Experiences
A mechanic shared restoring a 1979 Ford diesel engine where incorrect injection timing caused hard starting and excessive smoke. After realigning the pump timing marks and carefully securing the pump, the engine regained smooth idle and better throttle response.
Another operator noted that maintaining timing during pump replacement was critical; a minor misalignment caused a noticeable drop in power until corrected.
Maintenance and Diagnostic Advice

• Periodically check injection pump timing as part of regular maintenance.
  
• Monitor engine performance for signs of timing drift like rough running or smoke.
  
• Inspect timing gear and related components for wear.
  
• Keep detailed records of timing adjustments and service performed.
  
• Use quality fuel and keep fuel filters clean to prevent injection system clogging.
  

Technical Glossary

• Injector nozzle: The component that sprays fuel into the combustion chamber.
  
• Timing gear: The gear driving the injection pump linked to the engine camshaft or crankshaft.
  
• Advance mechanism: Adjusts fuel injection timing based on engine speed and load.
  
• Compression stroke: The phase in the engine cycle where the piston compresses the air-fuel mixture.
  
• Idle speed: Engine speed at which the engine runs smoothly without load.
  

Summary of Injection Pump Timing Procedure

• Clean and identify timing marks on engine and pump.
  
• Rotate engine to TDC on cylinder 1 compression stroke.
  
• Align crankshaft timing marks to TDC.
  
• Adjust injection pump position to timing reference.
  
• Secure pump bolts and verify alignment.
  
• Reassemble and start engine.
  
• Fine-tune timing if necessary with timing light or diagnostic tools.
  

Conclusion
Correctly timing the injection pump on the 1979 Ford A-62 268CID turbo diesel engine is essential for optimal engine performance and longevity. Through careful alignment of timing marks and adherence to factory specifications, operators can prevent common issues such as hard starting, smoke, and power loss. This procedure, combined with regular maintenance, ensures the engine delivers reliable power in demanding applications. Understanding the technical principles behind injection pump timing also aids mechanics and enthusiasts in diagnosing and addressing fuel delivery issues effectively.