Injection Timing Correction Procedure on Certain C3.8 Engines {0781, 0782, 1000, 1920} Caterpillar

Compact Track Loader

299D (S/N: GTC1-UP; HCL1-UP)

299D XHP (S/N: NLC1-UP; JST1-UP)

299D2 (S/N: FD21-UP; BY41-UP)

299D2 XHP (S/N: DX21-UP; DX91-UP)

Compact Wheel Loader

910K (S/N: AY41-UP)

914K (S/N: CD21-UP)

Multi Terrain Loader

297D (S/N: BE71-UP)

297D XHP (S/N: HP71-UP)

297D2 (S/N: BL71-UP)

297D2 XHP (S/N: HP21-UP)

Skid Steer Loader

272D (S/N: GSL1-UP; B5W1-UP)

272D XHP (S/N: ETL1-UP; SHY1-UP)

272D2 (S/N: BL21-UP)

272D2 XHP (S/N: MD21-UP)

Introduction

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

If the crankshaft, gear case and/or crank gear are replaced, it is necessary to perform the injection timing correction procedure. The following steps show how to calculate/determine the new injection timing by measuring angular deviation between the crankshaft TDC and Crank Position sensor detected TDC.

Note: Once complete the engine ecm must be reprogrammed with the new injection timing value. Follow all Steps below.

Procedure

Show/hide table

Illustration 1	g06220080
(1) TC Mark (Flywheel Housing) (2) TC Mark (Flywheel)

1. Remove valve cover, injector, and rocker arm. Bring the piston of cylinder 4 to TDC.
   Show/hide table

   Illustration 2	g06220082
   (3) Dial Gauge (4) Valve (5) O-ring

2. Remove the #4 exhaust valve bridge arm and valve spring. Insert a small O-ring (5) so the valve (4) does not fall into the cylinder.

3. Set the dial gauge (3) on the tip of the valve (4).
   Show/hide table

   Illustration 3	g06220083
   (6) Tri-sqaure (7) Flywheel Housing (8) Flywheel

   Show/hide table

   Illustration 4	g06220087
   (7) Flywheel Housing (8) Flywheel (9) Reference Line

4. Turn the flywheel counterclockwise and measure the position where the tip of the valve is highest.

5. Stop the flywheel at the position where the tip of the valve is the highest. Put a tri-sqaure (6) on the flywheel housing (7) and the flywheel (8) and draw a reference line (9).

   Do not drop the valve (4) into the cylinder. When measuring the highest position of the tip of the valve do not rotate the flywheel clockwise. If you go past the highest point of the valve, back up the flywheel slightly and measure the highest point of the valve. The reference line (9) indicates the TDC of the crankshaft.

   Show/hide table

   Illustration 5	g06220092
   (10) Tester (11) Crankshaft Position Sensor

   Show/hide table

   Illustration 6	g06220095
   (11) Crankshaft Position Sensor (12) Ground Terminal (13) Output Terminal

6. Connect the engine harness and the main switch. Connect battery.

   Attach the tester (10) to the output terminal (13) and the ground terminal (12) of the crankshaft position sensor (11). Turn the main switch "ON". Turn the flywheel and make sure that the voltage of the crankshaft position sensor goes from 0→ 5 V or 5 → 0 V.

   Show/hide table

   Illustration 7	g06220100
   (14) Pulsar Gear (15) 14th Tooth (16) Missing Teeth

7. Rotate the flywheel and align the crankshaft position sensor to the part of the pulsar gear (14) that is missing teeth (16). The 14th tooth (15) from the missing teeth is the standard. Slowly turn the flywheel counterclockwise and stop the flywheel at the point where the needle of the tester changes momentarily from 0→ 5 V, the 14th tooth. That point is where the crankshaft position sensor detects TDC.
   Show/hide table

   Illustration 8	g06220101
   (17) Crankshaft TDC (18) Detection Point of Crankshaft Position Sensor TDC

   Show/hide table

   Illustration 9	g06220104
   (19) Interval

8. Set the tri-square (6) on the reference line (9) on the flywheel housing side and mark the detection point of the crankshaft position sensor TDC (18) on the flywheel.

9. Measure the interval (19) between the crankshaft TDC (17) and the detection point of the crankshaft position sensor TDC (18).

10. Calculation of the fuel injection timing correction 1 mm (0.039 inch): 0.342°.

    Corrected angle = 0.342° X actual interval.

11. Overwrite the injection timing correction value on the engine ecm registration website refer to REHS9707, "Registering Diesel Particulate Filter (DPF), Diesel Oxidation Catalyst (DOC), Fuel Injector and Diesel Exhaust Fluid (DEF) Injector Serial Numbers on C2.4, C3.3B, and C3.8 Machine Engines".

    Once the injection timing correction values have been registered, you may follow the Engine ECM flashing procedure to obtain the new DPK flash file found in REHS9223, "Electronic Control Module (ECM) & Dosing Control Unit (DCU Flashing Procedure for the C2.4, C3.3B and C3.8 Engines".