G3600 A4 Engines Spark Plug Life Is Short Caterpillar


Spark Plug Life Is Short
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G3600 A4 Engines [KENR9774]
ELECTRICAL AND STARTING SYSTEM
IGNITION GP-GAS ENGINE
G3600 A4 Engines Spark Plug Life Is Short
1.1. Probable Causes
2.1. Recommended Actions

Probable Causes

  • Spark plug

  • Air/fuel ratio

  • Engine overload

  • Contamination

Recommended Actions

Table 1
Troubleshooting Test Steps  Values  Results 

1. Inspect the Spark Plug

A. Check the spark plug for wear.

B. Check the spark plug for combustion leaks above the gasket.

C. Check the insulator for cracks.

D. Check for the correct spark plug.

E. Check the spark plug gap.
 

Spark plug
 

Result: The spark plug is OK.

Proceed to Test Step 2.

Result: The spark plug is NOT OK.

Repair: Install a new spark plug. Refer to the Parts Manual, "Ignition Gp - Gas Engine" for the correct spark plug.

Set the spark plug gap according to Specifications, "Gas Engine Ignition".

If the problem is not resolved, proceed to Test Step 2.
 

2. Check the 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 AVSpare Software, LERW4485, "Gas Engine Rating Pro (GERP)".

C. Verify that the fuel supply pressure is adequate and stable.

D. Verify that the exhaust emissions are correct.
 

Air/Fuel Ratio
 

Result: The air/fuel ratio is OK.

Proceed to Test Step 3.

Result: The air/fuel ratio is NOT OK.

Repair: Use Cat ET to program the results for the "Fuel Specific Heat Ratio", "Fuel Quality", and "Gas Specific Gravity" parameters. Refer to Systems Operation, "Electronic Control System Parameters" for additional information.

Program the "Fuel Quality" parameter to the average value of the LHV. Adjust the engine operation according to Testing and Adjusting, "BTU and Precombustion Chamber Adjustments".

If the problem is not resolved, proceed to Test Step 3.
 

3. Check for Engine Overload

Note: Higher loads reduce the service life of spark plugs.
 

Load
 

Result: The engine is not being overloaded.

Proceed to Test Step 4.

Result: The engine is being overloaded.

Repair: Reduce engine load to an acceptable limit.

If the problem is not resolved, proceed to Test Step 4.
 

4. Check for Contamination in the Air/Fuel Mixture

A. Make sure that the equipment that treats the fuel prior to the engine is operating properly.

B. Make sure that the air and the fuel are properly filtered. There must be no leaks that allow contamination to enter the systems.

C. Inspect the turbocharger for leaks. If a turbocharger is leaking engine oil, the engine oil can contaminate the inlet air.
 

Contamination
 

Result: The Air/Fuel mixture is contaminated.

Repair: Perform any necessary repairs. For information on gas pretreatment equipment, refer to the Original Equipment Manufacturers (OEM) service information.

Verify that the repair eliminated the problem.
 

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).

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