How To - Set DS4 Injection Pump Timing

How To - Set DS4 Injection Pump Timing

  1. Use the "Time Set" feature and move the pump until you get an average "Actual Timing" reading of 3.5 (average). It will fluctuate around some, inherently.  This gets the pump in the correct position to move to step 2.
    1. Advanced users can often skip the TIME SET command but novice users should not.  This is because it makes it 100x faster to get the pump into an acceptable position without second guessing.
    2. Not all scan tools can command this function. You may become frustrated with the process if you find yourself in this situation. Getting ahold of a TECH II is the answer.
  2. Perform "TDCO Learn" and notate what value is set for "TDCO" - Top Dead Center Offset
  3. Adjust pump in very small increments and perform "TDCO Learn" until you achieve the final value desired. Factory setting is -0.50. Acceptable factory range was -0.25 to -0.75.  
  4. Perform a final tightening of the 3 pump retaining nuts to ensure it stays in place
Note: If TDCO learn keeps returning (OBDI -1.94/+1.94)(OBDII -2.46/+2.46, then you need to go back to step 1 and use the "Time Set" Feature to get the pump back into an acceptable position to move to Step 2. Or, there's another mechanical issue present.
Helpful Video demonstrating this on a TECHII: