jcb G20 Operator's Manual page 131

Fuel injection lines leaking.
Fuel filter(s) blocked, fuel supply restricted.
Fuel is aerated.
Fuel lift pump not operating correctly (fuel supply in-
adequate).
Air intake or exhaust system blocked.
One or more fuel injector worn or malfunctioning
Exhaust leak at the manifold or turbocharger (if ap-
plicable).
Extra injector sealing washer installed under injector. Remove extra injector sealing washer.
Inlet and exhaust valve clearances set incorrectly.
Worn or malfunctioning fuel injection pump.
Engine compression low in one or more cylinders.
Engine in reduced torque or limp home mode.
Electrical engine fault.
Cause
Tachometer faulty.
Engine overloaded.
Throttle position sensor (TPS) system defective.
Fuel is aerated.
Fuel lift pump not operating correctly (fuel supply in-
adequate).
Fuel is contaminated or incorrect grade diesel fuel
used.
Fuel filter(s) blocked, fuel supply restricted.
Turbocharger wastegate actuator diaphragm rup-
tured. (turbocharged machines only)
124
Table 31. Engine - Will Not Reach Maximum RPM
9831/0650-3
Inspect and correct as required leaks in the high
pressure lines, fittings injector sealing washers, or
delivery valves.
WARNING: Fine jets of fluid at high pressure can
penetrate the skin. Keep face and hands well clear of
pressurised fluid and wear protective glasses. If fluid
penetrates your skin, get medical help immediately.
Check/replace the fuel filter(s). Check fuel lines for
restriction.
Check the fuel system for loose connections and
possible air ingress points. Rectify and bleed the fuel
system.
Check that the lift pump operates and delivers fuel to
the fuel injection pump. Check the correct electrical
wires for open or short circuits.
Visually check the air intake and exhaust system for
blockage or obstruction - remove as required. Check
the air filter elements for signs of blocking - replace
as required.
Check the electrical connections at the injectors.
Check/correct leaks in the manifold or turbocharger
gaskets. Look for a cracked manifold.
Set the valve clearances to the recommended clear-
ances.
Do all the necessary fault finding checks before re-
moval of the fuel injection pump.
Check the engine compression.
Investigate the fault using ServiceMaster.
Investigate the fault using ServiceMaster.
Remedy
Verify engine speed with hand tachometer. Correct
as required.
Verify high idle speed without load. Investigate oper-
ation to be sure correct gear is being used.
Check the throttle assembly.
Check the low pressure fuel system for loose con-
nections and possible air ingress points. Rectify and
bleed the fuel system.
Check that the lift pump operates and delivers fuel to
the high pressure fuel pump. Check the correct elec-
trical wires for open or short circuits.
Stop the engine.
Replace the fuel filters. Operate the engine with a
temporary supply of the correct grade of clean fuel.
Monitor the engine performance.
WARNING: Dirty fuel will cause damage to the high
pressure fuel pump and injectors.
Check/replace the fuel filter(s).
Check fuel lines for restriction.
Repair of replace turbocharger.
Maintenance
Fault-Finding
124