Fuel Injector - Test
This procedure assists in identifying the cause for an injector misfiring. Perform this procedure only after performing the Cylinder Cutout Test. Refer to Troubleshooting, "Injector Solenoid Circuit - Test" for more information.
- Check for air in the fuel, if this procedure has not already been performed. Refer to Testing and Adjusting, "Air in Fuel - Test".
- Remove the valve cover and look for broken parts. Repair any broken parts or replace any broken parts that are found. Inspect all wiring for the solenoids. Look for loose connections. Also look for frayed wires or broken wires. Ensure that the connector for the unit injector solenoid is properly connected. Perform a pull test on each of the wires.
Show/hide table
Electrical shock hazard. The electronic unit injector system uses 90-120 volts. |
Show/hide table
Do not open the high pressure fuel system without allowing the fuel system to purge. After the engine has shut down, allow the fuel system to purge for ten minutes. This operating fuel system contains high pressure. Exposure to high pressure fuel can result in personal injury. |
- Look for signs of fuel leakage. Investigate the source of the leaking fuel. Remedy the cause of the fuel leak.
- Check the valve lash setting for the cylinder of the suspect injector. Refer to Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust".
- Ensure that the bolt that holds the injector is tightened to the proper torque. In order to check the torque, loosen the bolt that holds the injector. Refer to Specifications, "Fuel Injector" for the torque value and installation of the injector.
- Remove the suspect injector and check the injector for signs of exposure to coolant. Exposure to coolant will cause rust to form on the injector. If the injector shows signs of exposure to coolant, remove the injector sleeve and inspect the injector sleeve. Replace the injector sleeve if the injector sleeve is damaged. Check the injector for an excessive brown discoloration that extends beyond the injector tip. If excessive discoloration is found, check the quality of the fuel. Refer to Testing and Adjusting, "Fuel Quality - Test". Replace the seals on the injector and reinstall the injector. Inspect the injector for deposits of soot that are above the surface of the seat of the injector. Deposits of soot indicate combustion gas leakage. The source of the leak should be found, and the source of the leak should be remedied. The injector will not need to be replaced if combustion gas leakage was the problem.
Note: The high pressure fuel line needs to be replaced after removing the injector. The high pressure line is a one use fuel line.
- If the problem is not resolved, replace the suspect injector with a new injector. In order to verify that the new injector is working properly, perform the Cylinder Cutout Test. Use the Caterpillar Electronic Technician (ET).
Caterpillar Information System:
C7 On-highway Engine Clean Gas Induction Cooler
C13 and C15 On-Highway Engines Compression Brake - If Equipped
C9 Generator Set Fuel System Primary Filter (Water Separator) Element - Replace
3500 Engines with EUI Option Fuel Injector
2005/06/06 New Ignition Transformers are Used {1561}
C9 Engine for Caterpillar Built Machines Air Inlet Heater - Remove
3500B and 3500C Generator Set Engines Engine Speed/Timing Sensor - Calibrate
C27 and C32 Industrial and Petroleum Engines Throttle Position Sensor Circuit - Test
TH48-E80 Petroleum Transmission Transmission Operation
C27 and C32 Generator Set Engines E362 Engine Overspeed
C4.4 Marine Generator Set Engines Crankcase Breather - Remove and Install
C7 On-highway Engine Electronic Control System Components
C27 and C32 Industrial and Petroleum Engines Ether Injection System - Test
C7 On-highway Engine Fuel System
G3500 Engines Air Starting Motor - Disassemble
C4.4 Industrial Engine Engine Electronics
2005/05/23 A New Fuel Transfer Pump Has Been Released {1256}
2014/08/07 A New Fuel Transfer Pump Has Been Released {1256}
C4.4 Industrial Engine Gauges and Indicators
C4.4 Industrial Engine Monitoring System
C9 Engine for Caterpillar Built Machines Air Inlet Heater - Install
3500 Generator Sets Reference Material
793F Off-Highway Truck Differential Warm-up and Break-in
C9 Engine for Caterpillar Built Machines Engine Oil Filter Base and Oil Cooler - Remove