MOTOR GP-AIR STG 0R9857 - Caterpillar

Note: Cold weather adversely affects the characteristics of the fuel. Refer to the engine Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation.
Table 4
Required Tooling for Fuel Pressure Sensor
8t-7860 Connector
110-6349 Fitting As
8t-0855 Pressure Gauge
6v-3990 Coupler
Illustration 1 g03758136
C9.3 Engines
(1) Fuel temperature sensor
(2) Unfiltered fuel pressure sensor
(3) Fuel pressure sensor
(4) Fuel filter baseNote: Do not use location (2) for measuring the fuel pressure. Follow the steps below.
Table 5
Troubleshooting Test Steps Values Results
4. Check the Fuel Pressure Sensor
A. Record the fuel pressure from Cat ET. Record the value in Table 6.
B. Remove the fuel pressure sensor .
C. Install a 8t-7860 Connector into the port of the pressure sensor .
D. Install the 110-6349 Fitting As onto the 8t-7860 Connector.
E. Install a 8t-0855 Pressure Gauge onto a 6v-3990 Coupler.
F. Install the 6v-3990 Coupler onto the 110-6349 Fitting As.
G. Record the fuel pressure from Cat ET and on the pressure gauge. Record the data in Table 6.
Pressure Sensor
Result: The gauge value of the fuel pressure is within 69 kPa (10 psi) of the fuel pressure reading shown in ET.
Proceed to Test Step 5.
Result: The gauge value of the fuel pressure is not within 69 kPa (10 psi) of the fuel pressure reading shown in ET.
Repair: Replace the pressure sensor. Verify that the problem has been resolved.
If the problem is not resolved, proceed to Test Step 5.
Table 6
Engine RPM Fuel pressure from Cat ET Fuel pressure from the mechanical gauge
800
1800
Table 7
Troubleshooting Test Steps Values Results
5. Replace the Fuel Filters
A. Replace the primary filter, the secondary filter, and the tertiary fuel filters.
The fuel system will need to be primed after the filters are replaced.
B. Reset all active codes by cycling the keyswitch to the Off position for 2 minutes.
Fuel Filters
Result: The problem has been resolved.
Return the engine to service.
Result: The problem has not been resolved.
Proceed to Test Step 6.
6. Check for Air in the Fuel System
A. Check for air in the fuel. Refer to Systems Operation/Testing and Adjusting, "Air in Fuel - Test" for the proper procedure
Air in the System
Result: Air is in the system.
Repair: Refer to Systems Operation/Testing and Adjusting, "Air in Fuel - Test" for the proper repairs.
Result: Air is not in the system.
Proceed to Test Step 7.
Illustration 2 g03429826
C9.3 Engines
(9) Anti-drain check valve
(10) Fuel return pressure regulator
Table 8
Troubleshooting Test Steps Values Results
7. Replace the Fuel Return Pressure Regulator
A. Replace the fuel return pressure regulator.
B. Inspect the anti-drain check valve for proper operation.
Replace Pressure Regulator
Result: The problem has been resolved
Return the engine to service.
Result: The problem has not been resolved.
Proceed to Test Step 8.
8. Replace the Transfer Pump
A. Replace the transfer pump.
For information about testing the transfer pump, Refer to Testing and Adjusting, "Fuel System Pressure - Test".
Transfer Pump
Result: The transfer pump was replaced.
Repair: Reset all active codes and clear all logged codes by using Cat® ET.
Verify that the problem has been resolved.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC