G3306B Petroleum Generator Set Engines Caterpillar

The Electronic Control Module (ECM) calibrates the mechanical differences between the Top Center (TC) of the flywheel and the TC of the camshaft. Prior to placing the engine into service, a timing offset calibration must be performed on the engine. The timing calibration is used to time the ECM to the TC of the No. 1 piston. A timing light is used in order for the technician to provide the ECM with the actual TC of the flywheel. The offset is programmed into the ECM via Cat^® Electronic Technician (Cat ET) Service Tool.

An engine speed/timing sensor is used to detect the TC of the camshaft. The signal is provided to the ECM.

A timing calibration must be performed on the engine if the ECM has been replaced and the copy configuration function is not used. Also, the timing must be calibrated if work has been performed on the front gear train of the engine. Perform the following procedure in order to calibrate the engine timing:

1. Connect Cat ET to the service tool connector. Establish communications with the engine ECM. Ensure that the current configuration for the engine timing is correct:

   1. Enter the configuration screen. Locate the following parameters:
      • First Desired Timing

      • Desired Engine Timing Offset

   2. Obtain the methane number for the current gas that is being used for the engine. The methane number can be determined by using the Gas Engine Rating Pro (GERP). Be sure to reference the most recent gas analysis for the engine.

      A free copy of GERP can be obtained from the following link and searching for GERP in the search field located in the upper right-hand corner:

      http://catoilandgas.cat.com
      

      More information regarding the GERP program can be obtained from the website listed above or your dealer.

      Note: If the fuel composition at a given site changes significantly (> 5 Methane Number points), the timing will need to be reset. Contact your dealer or use GERP if such a change occurs. GERP can provide the maximum rating capability for altitude and ambient air temperatures at a given site.

   3. Use the methane number from the gas analysis to obtain the ignition timing that is specified for this engine. This information is available from the performance data that is provided for the engine or as obtained from GERP. Refer to the Technical Marketing Information (TMI) for the performance data for your engine.

   4. Program the parameter for First Desired Timing with the ignition timing that is from the performance data sheet for your engine or as obtained from GERP.

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Illustration 1	g01960893
Location of the timing hole (left side of the flywheel housing) (1) Timing indicator (2) Inspection plug

2. Remove inspection plug (2) that is on the left side of the flywheel housing.

3. Install the timing light on the engine.

   1. Connect the power leads to the terminals to battery power.

   2. Connect the magnetic pickup lead around the spark plug wire that is for the No. 1 cylinder.

4. Start the engine. Allow the engine to run at the high engine idle.

5. Use the timing light to check the actual ignition timing for the engine. Ensure that the actual ignition timing matches the timing that is programmed for First Desired Timing.

   If the actual ignition timing does not match First Desired Timing, reprogram the parameter for Desired Engine Timing Offset in order to adjust the actual ignition timing for the engine.

   The timing calibration is complete when the timing at the flywheel matches the ignition timing that is specified from the performance data sheet.

6. Restore the engine to the original configuration. Place the engine into service.