CX210/CX240 ELECTRONIC FUEL SYSTEM
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CX EXCAVATORS
FUEL SYSTEM TROUBLESHOOTING
Retrieval of fault code information from the Case 24 Valve Engine Control Module can be
done from the vehicle instrument monitor. The Service manual and the troubleshooting
section of this manual cover the fuel system diagnostics.
When Case 24 Valve, 5.9 Liter Engine running or performance problems are encountered,
use the following troubleshooting steps. Refer to the TS section of the Service Manual for
troubleshooting trees for customer complaints.
• Bleed air from the system. Air can be removed from the system by running the electric lift
pump. Momentarily bumping the crank mode of the ignition key starts a 25 second cycle
of the lift pump. This allows fuel to fill the system, venting any air entrapment through the
overflow valve and back to the fuel tank. Bleeding air from the high pressure lines
requires loosening the connector fittings on at least two high pressure lines and cranking
the engine until clear fuel is present.
• Install a test connector at the inlet to the fuel filter. Install a clear tube with a shut off valve
between the test connector and the fuel tank. Run the engine at full throttle. Slowly open
the valve and look for air in the discharging fuel. Air in the fuel indicates a restriction in the
inlet or insufficient lift pump pressure..
• Tee in a test connector at the inlet of the lift pump. Run the engine at wide open throttle.
Restriction at the lift pump inlet must not exceed 6 in. Hg. Restrictions greater than 6 in.
can be caused by the inline filter or the tank strainer.
• Measure lift pump discharge pressure. Install a test connector at the fuel filter outlet.
Cranking pressure must not exceed 7 PSI while pressure at low idle must be at least 10
PSI. If running pressure is low suspect the mesh screen in the lift pump inlet.
• Measure the pressure drop across the filter. Install connectors at the inlet and outlet of
the filter. Measure the pressure before and after the filter while running at wide open
throttle. The differential pressure must be less than 5 PSI.
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