BRACKET 5129044 - Caterpillar

Illustration 1 g06223838Note: The engine speed and load must be greater than 750 RPM and 50% Load to tune, however always tune the engine to the highest load and speed obtainable.Engine misfire must be corrected before proceeding with this adjustment. Tuning the engine with misfire present will result in an engine fuel flow that is too high in the misfiring cylinders, resulting in unbalance cylinder combustion. The engine might have the correct emissions but it will not run smoothly. Misfire is determined from engine spark plug cylinder number misfire rate in Cat ET.If the engine misfire rate is greater than 5% correct the cause of the misfire before continuing on.Follow these steps for the G3600 A4:
Illustration 2 g06223885
Enter the Fuel Specific Heat Ratio, LHV, and Specific Gravity to the values indicated by the gas analysis entered into Caterpillar software GERP to obtain the correct values.
Before you start the engine, prepare to connect an emissions analyzer to the exhaust outlet. Make sure that the emissions analyzer is correctly calibrated. The pickup must extend into the exhaust stream for at least 10 cm (4 inch). Do not connect the analyzer until the engine is warmed up and you are ready to tune the engine. This practice will extend the life of the analyzer sensors. Initial start-up and start-up after major work.
The engine can be started and loaded prior to the tuning. If NOx sensor cal is not known, disable NOx feedback before starting the engine and tune the NOx sensor. For startups of this type leave the needle valves set to the previous positions. If the previous needle valve positions are not known, screw all needle valves clockwise to the fully closed position. Then turn each needle valve 2.5 turns counterclockwise. The 2.5 turns open position can always be used as a default position. The setting can also be used as a starting point for tuning if the previous settings are unknown or do not provide the desired effect.
Start the engine and let it warm up. Operate the engine at the desired load and speed until the coolant temperature and oil temperature are stable. Approximately 1 hour is required for the warm up. After the engine is warmed up and stabilized, connect the emissions analyzer and turn on the analyzer.Note: Do not change the factory settings on a new engine until the engine has been operated under load and the NOx is verified. Often the factory settings only require minor adjustment or do not require adjustment at all.
Illustration 3 g06223890
Put engine back into NOx feedback enabled mode and allow emissions to stabilize. Verify the NOx sensor is reading within +/- 10ppm of the emissions analyzer, if it is not calibrate the NOx sensor.
Illustration 4 g06223893
Use Cat ET to switch the engine control system to the "PC CAL" mode. Under "Service", select "Engine Calibrations". Then select "Prechamber Calibration".Note: Do not exit the "PC CAL" mode while you tune the engine (adjust the needle valves). The "PC CAL" mode on the G3600 A4 is used to