MANIFOLD 1402863 - Caterpillar

Probable Causes
Fuel system
Connectors and wiring
Speed/Timing sensor
Ignition system
Engine overloadRecommended Actions
Unburned gas in the air inlet and exhaust system may ignite when the engine is started. Personal injury and/or property damage may result.Before starting an engine that may contain unburned gas, purge the unburned gas from the air inlet and exhaust system. Refer to the topic on purging unburned gas in the "Starting the Engine" section.
Gaseous fuel is present. Personal Injury or Death can result from an open flame or spark igniting the gaseous fuel causing an explosion and/or fire. Always use a gas detector to determine the presence of gaseous fuel when maintaining and servicing. Contact your local gas provider immediately for assistance in the event of a leak.
Table 1
Troubleshooting Test Steps Values Results
1. Check the Fuel System
Note: The following conditions can cause the engine to malfunction:
- Low fuel pressure
- High fuel pressure
- Poor fuel quality
- Incorrect air/fuel ratio
A. Obtain a fuel analysis.
Note: If the quality of the gas is inconsistent, obtain several analyses over a period of time.
B. Enter the data into Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)".
C. Verify that the fuel supply pressure is adequate and stable.
D. Verify that the size of the fuel line is sufficient.
E. Inspect the fuel system for leaks.
Note: Always use a gas detector to determine the presence of gaseous fuel. Contact your local provider of gas immediately for assistance.
F. Inspect the following fuel system components:
- Fuel filter
- Gas pressure regulator
- Gas shutoff valve
- Gas shutoff valve solenoid
Fuel System
Result: The fuel system is OK.
Proceed to Test Step 2.
Result: The fuel system is NOT OK.
Repair: Repair or replace damaged fuel system components.
Use Cat ET to program the results for the "Fuel Specific Heat Ratio", "Fuel Quality", and "Gas Specific Gravity" parameters. For more information, refer to Systems Operation, "Electronic Control System Parameters".
Program the "Fuel Quality" parameter to the average value of the LHV. Adjust the engine operation according to Systems Operation/Testing and Adjusting, "BTU and Precombustion Chamber Adjustments".
If the problem is not resolved, proceed to Test Step 2.
2. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Check for correct installation of the J1/P1 and J2/P2 ECM connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.
C. Check for correct installation of all other applicable connectors.
D. Check the power and ground connections to the ECM. Refer to Troubleshooting, "Electrical Power Supply - Test" for additional information.
Connectors and Wiring
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 3.
Result: There is a problem with the connectors and/or wiring.
Repair: Repair or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Speed/Timing Sensors
A. Make sure that the engine speed/timing sensors and the timing wheel are installed correctly.
Sensor
Result: The engine speed/timing sensors and the timing wheel are installed correctly.
Proceed to Test Step 4.
Result: The engine speed/timing sensors and/or the timing wheel are not