G3600 A4 Engines Fuel Pressure Problem Caterpillar


Fuel Pressure Problem
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1.1. Probable Causes
2.1. Recommended Actions

Use this procedure in order to troubleshoot a problem with the fuel system. Also, use this procedure if one of the following event codes is active or logged.

Table 1
J1939 Code and Description  Comments 
159-15
Engine Gas Supply Pressure : High - least severe (1) 
The fuel pressure has exceeded the trip point for the programmed delay time.
The code is logged. 
159-17
Engine Gas Supply Pressure : Low - least severe (1) 
The fuel pressure has exceeded the trip point for the programmed delay time.
The code is logged. 
1391-15
Engine Fuel Valve Differential Pressure : High - least severe (1) 
The fuel pressure has exceeded the trip point for the programmed delay time.
The code is logged. 
1391-17
Engine Fuel Valve Differential Pressure : Low - least severe (1) 
The fuel pressure has exceeded the trip point for the programmed delay time.
The code is logged. 
1392-15
Engine Air to Fuel Differential Pressure : High - least severe (1) 
The fuel pressure has exceeded the trip point for the programmed delay time.
The code is logged. 
1392-17
Engine Air to Fuel Differential Pressure : Low - least severe (1) 
The fuel pressure has exceeded the trip point for the programmed delay time.
The code is logged. 

Probable Causes

  • Air/Fuel pressure module

  • Filter

  • Fuel system

  • Gas pressure

  • Pressure regulator

Recommended Actions

Table 2
Troubleshooting Test Steps  Values  Results 

1. Check for Codes

A. Connect Cat® Electronic Technician (ET) to the service tool connector.

B. Look for active codes that are associated with the system for the event code.
 

Codes
 

Result: An associated code is active.

Repair: Troubleshoot any associated codes before continuing with this test.

Result: A code is active or logged.

Proceed to Test Step 2.
 

2. Check the Air/Fuel Pressure Module

A. Connect Cat ET.

B. Use Cat ET verify that the calibration value for fuel pressure is within the range of −3 to 3 kPa (−0.435 to 0.435 psi).

Note: A valid calibration value is required in order to operate the engine.

C. If a 1392-13 Engine Air to Fuel Differential Pressure : Out of Calibration is active, perform a calibration. Refer to Troubleshooting, "Air/Fuel Pressure Module - Calibrate" for additional information.  

Module
 

Result: The gauge value of the fuel pressure is reasonable when compared to the fuel pressure reading shown in ET.

Proceed to Test Step 3.

Result: The gauge value of the fuel pressure is not reasonable when compared to the fuel pressure reading shown in ET.

Repair: Replace the pressure sensor. Reset all active codes and clear all logged codes by cycling the main disconnect switch to the Off position.

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

3. Check the Fuel Filter

A. Measure the fuel filter's differential pressure according to Operation and Maintenance Manual, "Fuel System Fuel Filter Differential Pressure - Check".
 

Fuel Filter
 

Result: The fuel filter is OK.

Proceed to Test Step 4.

Result: The fuel filter is NOT OK.

Repair: Replace the filter element.

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

------ WARNING! ------

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 3
Troubleshooting Test Steps  Values  Results 

4. Check the Fuel System

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 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 5.

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. 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 5.
 

5. Adjust the Gas Pressure Regulator

Note: The fuel pressure must be stable to ± 1.7 kPa (± .25 psig).
 

448 ± 34 kPa or 65 ± 5 psig
 

Result: The gas pressure is NOT OK.

Repair: Adjust the gas pressure regulator. Refer to Testing and Adjusting, "Pressure Regulating Valve" for additional information.

If the gas pressure regulator cannot be adjusted to the correct setting, repair the regulator or replace the regulator.

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).