Testing Yanmar AL Fuel Injection Pump

I. Pump Adjustment

1. Preparation
   1. Mount pump on test stand using Yanmar mounting flange 121978-51010.
   2. Install Yanmar rack indicator.
   3. Ensure the total rack travel is 13.5 to 14.5 mm and that the
      rack moves smoothly thru the full length of it's travel.
   4. Add 400 cc of engine oil to pump.
   
   
2. Top Clearance Adjustment
   1. Remove delivery valve holder and delivery valve.
   2. After zeroing, install dial indicator, Yanmar special tool.
   3. Rotate camshaft to bring plunger to top dead center.
   4. Measure distance between top surface of barrel and top of plunger.
   5. If top clearance is not within specification, adjust to calibration spec with shim.
   6. Retorque delivery valve holder to 29 - 33 ft/lb.
   
   
3. Injection Timing Adjustment
   1. With throttle in wide open position, rotate pump by hand in clockwise
      rotation until injection begins on #1 cylinder.
   2. Check injection timing with flywheel scale. Re-check several times.
   3. Repeat steps #1 and #2 for each cylinder.
   4. Readjust top clearance of cylinders not within allowable timing range
      per calibration specification.
      
      

      Shim Thickness	Injection Timing Change
      Change	Cam Angle	Crank Angle
      0.1 mm (0.0039 in	0.4°	0.8°

      
      
   5. Important: Top clearance must always be above 0.3 mm.
   
   
   
4. Testing Plunger Pressure
   1. Install plunger gauge to delivery valve holder.
   2. Operate pump at 200 RPM with the rack in shutoff position.
   3. Slowly move rack to fuel delivery position until pressure gauge reaches
      500 kg/cm2 (7110 psi).
   4. Immediately return rack to no fuel position.
   5. Check for external leaks or sudden pressure drop.
   6. If 500 kg/cm2 pressure can not be reached, replace plunger & barrel.
   7. Keep pressure guage installed for delivery valve test.
   
   
5. Delivery Valve Leakage Test
   1. Operate pump at 200 RPM with the rack in shutoff position.
   2. Slowly move rack to fuel delivery position until pressure gauge reaches
      120 kg/cm2 (1706 psi).
   3. Measure time interval for pressure to drop from 100 kfg/cm2 to 90 kgf/cm2 (1422 - 1280 psi).
   4. If interval is less than 5 seconds, clean or replace delivery valve and re-test.
   
   
6. Injection Volume Adjustment
   1. Lock rack at rated position, using special bolt.
   2. Adjust pump to rated RPM.
   3. Check delivery volume per calibration specifications.
   4. Correct delivery of each cylinder as follows:
      1. Lock rack in shutoff position.
      2. Loosen barrel flange lock nuts.
      3. Rotate barrel to right or left to increase or decrease fuel.
   5. Repeat steps A through C for remaining checkpoints shown in calibration specs

II. Governor Adjustment

1. NOTE: If pump uses torque spring, destroke spring using special nut.
   1. Operate pump at rated speed with throttle in wide open position.
   2. Adjust rack to the rated position using fuel limit bolt and lock nut.
   3. Confirm that rated volume is within calibration specification.
   4. Readjust fuel limit bolt as necessary.
   
   
2. High Idle Adjustment
   1. Operate pump at high idle speed with throttle in wide open position.
   2. Adjust volume to calibration specification with the high idle bolt.
   
   
3. Low Idle Adjustment
   1. Place throttle lever in idle position.
   2. Operate pump at low idle speed and check volume.
   3. Adjust delivery volume to calibration spcification with the low idle bolt.
   
   
4. Cranking Speed Delivery
   1. Operate pump at start speed with throttle in wide open position.
   2. Confirm delivery volume per calibration data.
   
   
5. Torque Rise Adjustment
       (Only for pumps equipped with torque or angleich springs)
   1. Torque Spring Models
      1. Remove special nut installed prior to fuel limit adjustment
      2. Operate pump at rated load speed with throttle in the wide open position.
      3. Slowly reduce pump speed to peak torque and confirm the rack moves
         smoothly to peak torque position.
      4. Confirm the injection volume is within specification as per test plan.
   2. Angleich Spring Models
      1. To Test:
         1. Operate pump at rated speed WOT.
         2. Slowly reduce pump speed to peak torque and onfirm that rack moves smoothly to pek torque position.
         3. Confirm that injection volume is within specification per calibration specs.
      2. To Adjust:
         1. Operate pump at rated load speed (WOT).
         2. Adjust delivery volume with angleich spring capsule.
         3. Retorque angleich spring capsule locknut to 2.5 to 3.0 kg/m.
         4. Operate pump at rated speed (WOT) and confirm rack is at rated position
            as per calibration specs.
   
   
   1. Smoke Cut Adjustment (For Applicable Models)
      1. Operate pump at smoke cut spring speed per calibration specs (WOT).
      2. Remove rear lower governor case cover.
      3. Adjust fuel quantity with smoke cut spring capsule.
      4. Torque locknut to 2.5 t0 3.0 kg/m.
      5. Increase pump speed to rated RPM.
      6. Confirm that rack smoothly returns to rated position.
      
      
   2. Fuel Shutoff
      1. Operate pump at rated speed with throttle in wide open position.
      2. Move fuel shutoff lever to shutoff position.
      3. Confirm that fuel delivery stops.