Troubleshooting can be difficult. The most common problems are identified in this troubleshooting manual. The symptoms, causes, and guidance for solving the problems are given.
Sometimes additional repair work is required beyond the repair which is recommended. Frequently, a problem does not exist in isolation. The problem can be a result of wear or damage to several parts which operate together as part of a system.
All possible problems and the probable causes cannot be listed. The technician must follow a logical process of eliminating possible causes and identifying the specific causes of the problems.
Troubleshooting the Fuel Injection Nozzles
Note: Be careful when you are handling the fuel injection nozzles in order to prevent damage to the orifices, threads, and other surfaces. When a fuel injection nozzle is installed, make sure that all surfaces and threads are clean.
The procedures which require disassembly or the adjustment of the fuel injection nozzle only relate to engines with the following serial numbers:
- 4ZK1-UP
- 6FK1-UP
- 7AK1-UP
- 1ML1-UP
Do not disassemble the fuel injection nozzles and do not adjust the fuel injection nozzles on engines with the following serial numbers:
- 5YS1-UP
- 7MS1-UP
- 2PW1-UP
- 3GW1-UP
Replace the fuel injection nozzle on these engines if the fuel injection nozzle does not operate correctly. These fuel injection nozzles do not have serviceable parts.
Refer to Specifications, "Fuel Injection Nozzles" for additional information.
The Engine is Difficult to Start or the Engine Runs Rough.
- The fuel injection nozzle does not seal correctly in the cylinder head.
Make sure that the seals and the mating surface of the cylinder head are clean. The seal that is formed by the anti-seize compound on the threads of the fuel injection nozzle may be broken. Make sure that the fuel injection nozzle is tightened to the correct torque in the threaded hole of the cylinder head.
- Extra seat washers were not removed from the threaded recess in the cylinder head for the fuel injection nozzle. There is debris on the mating surface of the cylinder head with the seat washer.
Remove any extra seat washer or debris.
- The connections of the high pressure fuel line leak.
Tighten the fittings of the high pressure fuel line.
- The fuel injection nozzle does not operate correctly.
Note: This step does not include (S/N: 5YS; 7MS; 2PW; 3GW) engines. The fuel injection nozzles for these engine serial numbers are not serviceable. Adjustment of these fuel injection nozzles should not be made. If any problem with the internal components of these fuel injection nozzles exist, the fuel injection nozzle should be replaced.
Make sure that the mounting bolts for the clamp and the components of the fuel injection nozzle are tightened to the correct torques. Make sure that the seal and the spacer are positioned correctly.
Test the fuel injection nozzle on a nozzle tester.
- The incorrect fuel injection nozzle is installed.
Make sure that all fuel injection nozzles have the correct identification code for the engine. Refer to the Specifications Module, "Fuel Injection Nozzles".
The Engine Exhaust has Too Much Black Smoke or the Engine Overheats.
- Extra seat washers were not removed from the threaded recess in the cylinder head for the fuel injection nozzle. There is debris on the mating surface of the cylinder head with the seat washer.
Remove any extra seat washer or debris.
- The fuel injection nozzle does not operate correctly.
Refer to "The Engine is Difficult to Start or the Engine Runs Rough.".
- The incorrect fuel injection nozzle is installed.
Make sure that all fuel injection nozzles have the correct identification code for the engine. Refer to the Specifications Module, "Fuel Injection Nozzles".
The Engine has Lost Power and the Engine Uses Too Much Fuel.
- Extra seat washers were not removed from the threaded recess in the cylinder head for the fuel injection nozzle. There is debris on the mating surface of the cylinder head with the seat washer.
Remove any extra seat washer or debris.
- The connections of the high pressure fuel line leak.
Tighten the fittings of the high pressure fuel line.
- The fuel injection nozzle does not operate correctly.
Refer to "The Engine is Difficult to Start or the Engine Runs Rough.".
Test the fuel injection nozzle on a nozzle tester.
- The incorrect fuel injection nozzle is installed.
Make sure that all fuel injection nozzles have the correct code for the engine.
- A connection of the fuel return line leaks.
Inspect all connections of the low pressure fuel line for tightening to the correct torque.
The Engine is Misfiring, Running Rough, or Running Poorly.
- The fuel injection nozzle does not seal in the cylinder head.
Refer to "The Engine is Difficult to Start or the Engine Runs Rough.".
- Extra seat washers were not removed from the threaded recess in the cylinder head for the fuel injection nozzle. There is debris on the mating surface of the cylinder head with the seat washer.
Remove any extra seat washer or debris.
- The connections of the high pressure fuel line leak.
Tighten the fittings of the high pressure fuel line.
- The fuel injection nozzle does not operate correctly.
Refer to"The Engine is Difficult to Start or the Engine Runs Rough.".
Test the fuel injection nozzle on a nozzle tester.
- The incorrect fuel injection nozzle is installed.
Make sure that all fuel injection nozzles have the correct code for the engine.
- A restriction exists in the high pressure fuel line.
Inspect all high pressure fuel lines for damage.
- Fuel leaks through the cap nut or the retaining nut.
Make sure that the threads are clean. Tighten the nuts to the correct torque.
- Debris or damage exists on the needle valve or the body.
Visually inspect the needle and the body of the valve for carbon pitting, scoring, or other damage.
The Fuel Injection Nozzle Does Not Inject Fuel in the Correct Quantity or in the Correct Pattern.
- The setting of the opening pressure is incorrect.
Test the setting of the opening pressure. Adjust the setting to the correct pressure.
- The fuel injection nozzle is stuck.
Debris or damage exists on the fuel injection nozzle.
- The orifices are blocked.
Inspect the orifices for carbon buildup. The fuel injection nozzle must be cleaned or replaced.
- The spring is damaged.
Replace the spring or the fuel injection nozzle.
- The needle valve or the body is damaged. The fuel injection nozzle makes a noise which is caused by vibration when the fuel is injected.
Visually inspect the needle valve and the body for carbon pitting, scoring, or other damage.
- The passage for the fuel return is obstructed.
Clean the passage in order to remove any carbon buildup or other debris.
- The cap nut is too tight.
Adjust the cap nut to the correct torque.
- The element of the air filter is dirty.
The element must be cleaned or replaced.
- A restriction exists in the tube between the air filter and the turbocharger.
Find the restriction and repair or replace the component.
- An air leak or a restriction exists in the line between the turbocharger and the intake manifold.
The component must be repaired or replaced.
- A restriction exists in the exhaust system.
The component must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The intake manifold is cracked, loose or the flange is distorted.
The intake manifold must be repaired or replaced.
- The exhaust manifold is cracked, loose, or the flange is distorted.
The exhaust manifold must be repaired or replaced.
- The turbine housing is damaged or restricted.
The turbine housing must be repaired or replaced.
- The bearings of the turbocharger are worn.
Replace the bearings.
- Excessive dirt exists in the compressor housing.
Clean the compressor housing.
- Carbon has collected behind the rotor of the turbine.
Remove the carbon.
- The fuel injection pump is not operating correctly.
The fuel injection pump must be repaired or replaced.
- The fuel injection nozzles are worn or damaged.
The fuel injection nozzles must be repaired or replaced.
- The inlet valves and the exhaust valves are burned.
Replace the inlet valves and the exhaust valves. Determine the cause of the damage to the valves.
- The piston rings are worn.
Replace the piston rings.
- The actuator of the wastegate is not operating correctly.
The actuator must be adjusted or replaced.
- The valve of the wastegate is not operating correctly.
The valve must be repaired or replaced.
- The element of the air filter is dirty.
The element must be cleaned and replaced.
- A restriction exists in the tube between the air filter and the turbocharger.
The component must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The intake manifold is cracked, loose or the flange is distorted.
The intake manifold must be repaired or replaced.
- The drain pipe for the lubricating oil is restricted.
The drain pipe must be repaired or replaced.
- Air or combustion gas is leaking through the seals of the turbocharger.
Replace the seals.
- The bearings of the turbocharger are worn.
Replace the bearings.
- Excessive dirt exists in the compressor housing.
Clean the compressor housing.
- Carbon has collected behind the rotor of the turbine.
Remove the carbon.
- The element of the air filter is dirty.
The element must be cleaned or replaced.
- The crankcase breather is restricted.
The crankcase breather (if equipped), or the tubing must be cleaned or replaced.
- A restriction exists in the tube between the air filter and the turbocharger.
The component must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The intake manifold is cracked, loose or the flange is distorted.
The intake manifold must be repaired or replaced.
- The drain pipe for the lubricating oil is restricted.
The drain pipe must be repaired or replaced.
- Air or combustion gas is leaking through the seals of the turbocharger.
Replace the seals.
- The bearings of the turbocharger are worn.
Replace the bearings.
- Excessive dirt exists in the compressor housing.
Clean the compressor housing.
- Carbon has collected behind the rotor of the turbine.
Remove the carbon.
- Excessive anti-corrosion fluid exists in the turbocharger. This condition only exists on a new engine which has not been operated.
Clean the turbocharger in order to remove the anti-corrosion fluid.
- The high idle operates for an excessive period of time.
The fuel injection pump must be repaired or replaced.
- A restriction exists in the bearing housing of the turbocharger.
The bearing housing must be repaired or replaced.
- The element of the air filter is dirty.
The element must be cleaned or replaced.
- The crankcase breather is restricted.
The crankcase breather (if equipped), or the tubing must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The incorrect type of lubricating oil is being used.
Drain the lubricating oil. Install the correct quantity and type of lubricating oil.
- The drain pipe for the lubricating oil is restricted.
The drain pipe must be repaired or replaced.
- The turbine housing is damaged or restricted.
The turbine housing must be repaired or replaced.
- The bearings of the turbocharger are worn.
Replace the bearings.
- The piston rings are worn.
Replace the piston rings.
- Lubricating oil is leaking from the supply line.
The supply line must be repaired or replaced.
- The high idle operates for an excessive period of time.
The fuel injection pump must be repaired or replaced.
- A restriction exists in the bearing housing of the turbocharger.
The bearing housing must be repaired or replaced.
Excessive Lubricating Oil at the End of the Turbine
- The crankcase breather is restricted.
The crankcase breather (if equipped), or the tubing must be cleaned or replaced.
- A restriction exists in the exhaust system.
The component must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The drain pipe for the lubricating oil is restricted.
The drain pipe must be cleaned or replaced.
- The turbine housing is damaged or restricted.
The turbine housing must be cleaned or replaced.
- The bearings of the turbocharger are worn.
Replace the bearings.
- Carbon has collected behind the rotor of the turbine.
Remove the carbon.
- The piston rings are worn.
Replace the piston rings.
- Excessive anti-corrosion fluid exists in the turbocharger. This condition only exists on a new engine which has not been operated.
Clean the turbocharger in order to remove the anti-corrosion fluid.
- The high idle operates for an excessive period of time.
The fuel injection pump must be repaired or replaced.
- A restriction exists in the bearing housing of the turbocharger.
The bearing housing must be repaired or replaced.
Excessive Lubricating Oil at the Compressor End
- The element of the air filter is dirty.
Replace the element of the air filter.
- The crankcase breather is restricted.
The crankcase breather (if equipped), or the tubing must be cleaned or replaced.
- A restriction exists in the tube between the air filter and the turbocharger.
The component must be cleaned and replaced.
- A air leak or restriction exists in the line between the turbocharger and the intake manifold.
The component must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- Air or combustion gas is leaking through the seals of the turbocharger.
Replace the seals.
- The bearings of the turbocharger are worn.
Replace the bearings.
- Excessive dirt exists in the compressor housing.
Clean the compressor housing.
- The piston rings are worn.
Replace the piston rings.
- Excessive anti-corrosion fluid exists in the turbocharger. This condition only exists on a new engine which has not been operated.
Clean the turbocharger in order to remove the anti-corrosion fluid.
- The high idle operates for an excessive period of time.
The fuel injection pump must be repaired or replaced.
- A restriction exists in the bearing housing of the turbocharger.
The bearing housing must be repaired or replaced.
Lubricating Oil in the Exhaust Manifold
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The flow of lubricating oil is delayed to the turbocharger when the engine is started. Insufficient oil flows to the turbocharger when the engine is running.
Check the following components for correct operation:
- oil pump
- the engine oil bypass valve
- the bypass valve in the oil filter base
- oil filter
- viscosity of the oil
- restrictions in oil lines
- The lubricating oil is dirty.
Drain the lubricating oil. Install the correct type of lubricating oil. Replace the oil filter.
- The incorrect type of lubricating oil is installed.
Drain the lubricating oil. Replace the oil filter. Install the correct type of lubricating oil.
- The oil supply line from the oil pan is restricted.
The oil supply line must be repaired or replaced.
- The engine rpm increases too rapidly when the engine is started.
Check the fuel injection pump for correct operation and settings.
- The high idle operates an insufficient period of time.
Check the fuel injection pump for correct operation and settings.
- Lubricating oil is leaking from the oil supply line.
The oil supply line must be repaired or replaced.
- A restriction exists in the bearing housing of the turbocharger.
The bearing housing must be repaired or replaced.
- A restriction exists in the lubricating oil filter.
Clean the oil filter base and the housing for the oil filter. Check the operation of the bypass valve in the oil filter base. Replace the oil filter.
- The engine stopped too soon from a high load condition.
Check the following components for correct operation or damage:
- compressor impeller of the turbocharger
- coolant system
- fuel injection pump
- air/fuel ratio control
- wastegate
- valve lash
- fuel injection nozzles
The Inside of the Inlet Manifold is Wet.
- The element of the air filter is not sealed correctly. A connection between the air filter and the turbocharger is loose.
Inspect the element of the air filter and the air supply line to the turbocharger for correct installation.
- A restriction exists in the tube between the air filter and the turbocharger.
The component must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The flow of the lubricating oil is delayed to the turbocharger when the engine is started. Insufficient oil flows to the turbocharger when the engine is running.
Check the following components for correct operation:
- oil pump
- the engine oil bypass valve
- the bypass valve in the oil filter base
- oil filter
- viscosity of the oil
- restrictions in oil lines
- The incorrect type of lubricating oil is installed.
Drain the lubricating oil. Replace the oil filter. Install the correct type of lubricating oil.
- The oil supply line from the oil pan is restricted.
The oil supply line must be repaired or replaced.
- The bearings of the turbocharger are worn.
Replace the bearings.
- Excessive dirt exists in the compressor housing.
Clean the compressor housing.
- The engine rpm increases too rapidly when the engine is started.
Check the fuel injection pump for correct operation and settings.
- The period of time at high idle is insufficient.
Check the fuel injection pump for correct operation and settings.
- Lubricating oil is leaking from the oil supply line.
The oil supply line must be repaired or replaced.
- A restriction exists in the bearing housing of the turbocharger.
The bearing housing must be repaired or replaced.
- A restriction exists in the lubricating oil filter.
Clean the oil filter base and the housing for the oil filter. Check the operation of the bypass valve in the oil filter base. Replace the oil filter.
- The engine stopped too soon from a high load condition.
Check the following components for correct operation or damage:
- compressor impeller of the turbocharger
- coolant system
- fuel injection pump
- air/fuel ratio control
- wastegate
- valve lash
- fuel injection nozzles
- A restriction exists in the exhaust system.
The component must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The flow of the lubricating oil is delayed to the turbocharger when the engine is started. Insufficient oil flows to the turbocharger when the engine is running.
Check the following components for correct operation:
- oil pump
- the engine oil bypass valve
- the bypass valve in the oil filter base
- oil filter
- viscosity of the oil
- restrictions in oil lines
- The lubricating oil is dirty.
Drain the lubricating oil. Install the correct type of lubricating oil. Replace the oil filter.
- The incorrect type of lubricating oil is installed.
Drain the lubricating oil. Replace the oil filter. Install the correct type of lubricating oil.
- The oil supply line from the oil pan is restricted.
The oil supply line must be repaired or replaced.
- The incorrect type of lubricating oil is installed.
Drain the lubricating oil. Replace the oil filter. Install the correct type of lubricating oil.
- The oil supply line from the oil pan is restricted.
The oil supply line must be repaired or replaced.
- The turbine housing is damaged or restricted.
The turbine housing must be repaired or replaced.
- The bearings of the turbocharger are worn.
Replace the bearings.
- Carbon has collected behind the rotor of the turbine.
Remove the carbon.
- The engine rpm increases too rapidly when the engine is started.
Check the fuel injection pump for correct operation and settings.
- The period of time at high idle is insufficient.
Check the fuel injection pump for correct operation and settings.
- The fuel injection pump is not operating correctly.
The fuel injection pump must be repaired or replaced.
- The inlet valves and the exhaust valves are burned.
Replace the inlet valves and the exhaust valves. Determine the cause of the damage to the valves.
- Lubricating oil is leaking from the oil supply line.
The oil supply line must be repaired or replaced.
- A restriction exists in the bearing housing of the turbocharger.
The bearing housing must be repaired or replaced.
- A restriction exists in the lubricating oil filter.
Clean the oil filter base and the housing for the oil filter. Check the operation of the bypass valve in the oil filter base. Replace the oil filter.
- The engine stopped too soon from a high load condition.
Check the following components for correct operation or damage:
- compressor impeller of the turbocharger
- coolant system
- fuel injection pump
- air/fuel ratio control
- wastegate
- valve lash
- fuel injection nozzles
The Rotating Assembly of the Turbocharger does Not Rotate Freely.
- A restriction exists in the tube between the air filter and the turbocharger.
The component must be repaired or replaced.
- A restriction exists in the exhaust system.
The component must be repaired or replaced.
- The turbocharger is loose or the clamps and bolts on the turbocharger are loose.
Correctly position the turbocharger and tighten the clamps and bolts.
- The flow of the lubricating oil is delayed to the turbocharger when the engine is started. Insufficient oil flows to the turbocharger when the engine is running.
Check the following components for correct operation:
- oil pump
- the engine oil bypass valve
- the bypass valve in the oil filter base
- oil filter
- viscosity of the oil
- restrictions in oil lines
- The lubricating oil is dirty.
Drain the lubricating oil. Install the correct type of lubricating oil. Replace the oil filter.
- The incorrect type of lubricating oil is installed.
Drain the lubricating oil. Replace the oil filter. Install the correct type of lubricating oil.
- The oil supply line from the oil pan is restricted.
The oil supply line must be repaired or replaced.
- The engine rpm increases too rapidly when the engine is started.
Check the fuel injection pump for correct operation and settings.
- The period of time at high idle is insufficient.
Check the fuel injection pump for correct operation and settings.
- Lubricating oil is leaking from the oil supply line.
The oil supply line must be repaired or replaced.
- A restriction exists in the lubricating oil filter.
Clean the oil filter base and the housing for the oil filter. Check the operation of the bypass valve in the oil filter base. Replace the oil filter.
- The engine stopped too soon from a high load condition.
Check the following components for correct operation or damage:
- compressor impeller of the turbocharger
- coolant system
- fuel injection pump
- air/fuel ratio control
- wastegate
- valve lash
- fuel injection nozzles
The Turbocharger Makes Excessive Noise.
- The crankcase breather is restricted.
The crankcase breather (if equipped), or the tubing must be cleaned or replaced.
- The flow of the lubricating oil is delayed to the turbocharger when the engine is started. Insufficient oil flows to the turbocharger when the engine is running.
Check the following components for correct operation:
- oil pump
- the engine oil bypass valve
- the bypass valve in the oil filter base
- oil filter
- viscosity of the oil
- restrictions in oil lines
- The lubricating oil is dirty.
Drain the lubricating oil. Install the correct type of lubricating oil. Replace the oil filter.
- The incorrect type of lubricating oil is installed.
Drain the lubricating oil. Replace the oil filter. Install the correct type of lubricating oil.
- The oil supply line from the oil pan is restricted.
The oil supply line must be repaired or replaced.
- The turbine housing is damaged or restricted.
The turbine housing must be repaired or replaced.
- The period of time at high idle is insufficient.
Check the fuel injection pump for correct operation and settings.
- Lubricating oil is leaking from the oil supply line.
The oil supply line must be repaired or replaced.
- A restriction exists in the lubricating oil filter.
Clean the oil filter base and the housing for the oil filter. Check the operation of the bypass valve in the oil filter base. Replace the oil filter.
- The engine stopped too soon from a high load condition.
Check the following components for correct operation or damage:
- compressor impeller of the turbocharger
- coolant system
- fuel injection pump
- air/fuel ratio control
- wastegate
- valve lash
- fuel injection nozzles
- The engine starting procedure was incorrectly followed.
Make sure that the engine starting procedure is correctly followed.
- The Fuel Stop Control is in the "NO FUEL" position.
Turn the Fuel Stop Control to the "RUN" position. Make sure that the linkage of the fuel rack operates correctly.
- The fuel level is low in the tank. Air is in the fuel system.
Fill the fuel tank with fuel. Remove the air from the fuel system.
- The fuel is contaminated.
The fuel contains water, dirt, ice or wax.
- The cranking speed is too slow.
The engine oil is too thick. The connections of the battery cables to the starting motor are loose.
- The cold starting aid for the fuel injection pump does not operate correctly.
Inspect the cable connection and the electrical connection of the cold starting aid. Test the cold starting aid for correct operation.
- The fuel shutoff solenoid is not operating correctly.
Make sure that the fuel shutoff solenoid operates correctly. Replace a fuel shutoff solenoid that is faulty.
- The fuel transfer pump is not operating correctly. The fuel transfer pump was installed when the lobe of the camshaft was at maximum lift.
Check the fuel pressure when the engine is cranking. Remove the fuel transfer pump if the fuel pressure is too low. The fuel transfer pump must be repaired or replaced.
Install the fuel transfer pump with the lobe of the camshaft on minimum lift. Tighten the mounting bolts evenly.
- The fuel filter or the fuel lines are restricted. Excess water has built up in the fuel filter.
Check fuel lines and the fuel filter. Drain any water from the fuel filter.
- The operation of the fuel injection pump is not correct.
Check the timing of the fuel injection pump. Adjust the timing or replace the fuel injection pump. Check the timing of the drive gear for the fuel injection pump with the idler gear. The fuel injection pump must be repaired or replaced.
Make sure that the high pressure fuel lines are connected to the fuel injection nozzles in the correct order.
Make sure that the mounting bolts of the fuel injection pump are tightened to the correct torque. Inspect the fuel lines for leaks or restrictions. The damaged fuel lines or fittings must be repaired or replaced.
- The linkage of the accelerator or governor is faulty.
Tighten the retaining bolt if the accelerator lever on the fuel injection pump is loose. Adjust the cable for the accelerator lever if the accelerator lever moves to the stops. The linkage for the governor must be repaired or replaced.
- A fuel injection nozzle is not operating correctly.
Run the engine at the rpm that gives maximum misfiring or rough running. Then, loosen a fuel line nut on the injection line for each cylinder. Loosen one nut at a time. Then, tighten that nut before loosening the next fuel line nut. If loosening the fuel line nut does not affect the operation of the engine, the fuel injection nozzle is probably faulty. Test the fuel injection nozzle for that cylinder. Replace the faulty fuel injection nozzle.
Make sure that all of the fuel injection nozzles are the correct type for the engine. Test the pressure setting of the fuel injection nozzles.
Make sure that the fuel injection nozzles are properly sealed in the threaded ports. Make sure that the fuel injection nozzles are correctly aligned in the threaded ports and tightened to the correct torque. Ensure that seat washers are installed on the fuel injection nozzles correctly. Make sure that the bottom of the threaded ports are clean and free of debris. Make sure that the bottom of the threaded ports do not contain extra seat washers.
- The air inlet heater is faulty.
Test the air inlet heater. Replace the air inlet heater if the air inlet heater fails the test.
- The cylinders have low compression.
Starting the engine may be difficult in warm weather. The engine may not start in cold weather. Low compression is most frequently caused by the following conditions:
- Cylinder liners are worn.
- Piston rings are worn.
- The fuel injection nozzles are not seated correctly.
- The valve lash requires adjustment.
- The fuel injection pump timing is incorrect.
- The engine timing is incorrect.
- When an inlet valve or an exhaust valve is fully seated, gases leak past the valve head.
- The fuel filter or the fuel lines are restricted. Excess water has built up in the fuel filter.
Check the fuel lines and the fuel filter. Replace the fuel filter. Drain any water from the fuel filter.
- The operation of the fuel transfer pump is not correct.
Refer to "The Engine Will Not Start.".
- The air inlet or the exhaust system is restricted.
Inspect the air inlet and the exhaust systems. Remove any restrictions.
- Air is in the fuel system.
Find the air leak in the fuel system. Repair the fuel system.
The Engine Misfires or the Engine Runs Rough.
- The fuel pressure is low.
Make sure that the fuel tank has enough fuel. Look for leaks or faulty bends in all of the fuel supply lines. Test the outlet pressure of the fuel transfer pump.
- Air is in the fuel system.
Find the air leak in the fuel system. Repair the air leak.
- The valve lash is not correct.
Adjust the valve lash.
- The operation of the fuel injection pump is not correct.
Refer to"The Engine Will Not Start.".
- A fuel injection nozzle does not operate correctly.
Refer to "The Engine Will Not Start.".
- The engine mounts are not correctly tightened or mounted correctly. This condition also causes vibration.
Check the engine mounts for correct positioning. Check the bolts of the engine mounts for correct tightening.
- The fuel is contaminated with water, dirt, ice or wax.
Drain any water from the fuel tank or the fuel filter. If the fuel is contaminated by dirt, ice or wax, replace the fuel. For the proper removal and disposal of fuel, refer to the Disassembly and Assembly module.
- The cylinders have low compression.
Refer to "The Engine Will Not Start.".
The Engine Runs Evenly, but the Engine Loses Power.
- The cylinders have low compression.
Refer to "The Engine Will Not Start.".
- The operation of the fuel injection pump is not correct.
Refer to "The Engine Will Not Start.".
- The valve lash is not correct.
Adjust the valve lash.
- The air cleaner is restricted.
The air cleaner must be repaired or replaced.
- Air is in the fuel system.
Remove the air from the fuel system. Make sure that the fittings of the fuel lines are aligned and tightened correctly.
- The fuel transfer pump is not operating correctly. The fuel transfer pump is installed with the lobe of the camshaft on maximum lift.
Refer to "The Engine Will Not Start.".
The Engine Does Not have Enough Power.
- Fuel of poor quality is in the fuel system.
Remove the fuel from the fuel tank. Install a new fuel filter. Put a good grade of clean fuel in the fuel tank. For the proper procedures for the removal and disposal of fuel, refer to the Disassembly and Assembly module.
- The fuel pressure is low.
Make sure that sufficient fuel is in the fuel tank. Look for leaks or damaged bends in the fuel line between the fuel tank and the fuel transfer pump. Remove any air in the fuel system. Check the outlet pressure of the fuel transfer pump.
- The accelerator linkage is not properly adjusted.
Adjust the linkage for full travel. Replace faulty parts.
- The valve lash is not correct.
Adjust the valve lash.
- The operation of the fuel injection pump is not correct.
Refer to"The Engine Will Not Start." .
- A fuel injection nozzle is not operating correctly.
Refer to "The Engine Will Not Start.".
The Engine has Excessive Vibration.
- Fuel of poor quality is in the fuel system.
Refer to "The Engine Does Not have Enough Power.".
- A fuel injection nozzle is faulty.
Refer to "The Engine Will Not Start.".
The Engine has Valve Compartment Noise.
- Valve springs or locks are broken.
Install new parts. Broken locks can cause the valve to slide into the cylinder. Major damage to the engine can occur.
- The bolts and nuts, which hold the rocker arm assembly, are loose.
Tighten the bolts or nuts.
- The valve lash exceeds the specification.
Adjust the valve lash.
- The cylinder head gasket is faulty.
Install a new cylinder head gasket.
- The transmission oil cooler is faulty.
Replace the transmission oil cooler.
- The main bearing is damaged.
Inspect the main bearings and the bearing surface of the crankshaft. Replace damaged parts.
- The crankshaft is damaged.
Replace the crankshaft. Clean the engine thoroughly.
The Rocker Arm has Insufficient Movement and the Valve Lash Exceeds the Specifications.
- Lubrication of internal engine components is inadequate.
Check lubrication of the valves. There must be a strong flow of oil at engine high rpm, but only a small flow at low rpm. Oil passages must be clean.
- Rocker arm parts are worn.
If there is too much wear, install new parts or rocker arms. Adjust the valve lash.
- The end of the valve stem is worn.
Install new valves. Adjust the valve lash.
- The valve lash exceeds the specification.
Measure the valve lash. Adjust the valve lash.
- The pushrods are worn.
If there is too much wear, install new pushrods. Adjust the valve lash.
- The valve lifters are worn.
If there is too much wear, install new valve lifters. Adjust the valve lash.
- The lobes of the camshaft are worn.
Measure the valve lash. Check for free movement of the valves. Check for bent valve stems. Check for wear on the valve lifters. Replace faulty parts. Adjust the valve lash.
- The bolts and the nuts that hold the rocker arm assembly are loose.
Tighten the bolts and the nuts.
- The valve seat or the face of the valve is worn.
Recondition the cylinder head. Adjust the valve lash.
- The cylinder head gasket is faulty.
Install a new cylinder head gasket.
- The cylinder head is cracked or damaged.
Install a new cylinder head.
- The cylinder block is cracked or damaged.
Install a new cylinder block.
The Engine Exhaust has Too Much Black Smoke or Gray Smoke.
- The cylinders have low compression.
Refer to "The Engine Will Not Start.".
- The operation of the fuel injection pump is not correct.
Refer to "The Engine Will Not Start.".
- A fuel injection nozzle is not operating correctly.
Refer to "The Engine Will Not Start.".
- The inlet air is restricted.
Check the air cleaner for restrictions. The air cleaner must be cleaned or replaced.
- The air inlet heater does not operate or fuel leaks from the air inlet heater.
Test the air inlet heater. Check the operation of the control switch for the air inlet heater.
The Engine Exhaust has Too Much White Smoke or Blue Smoke.
- The engine contains too much lubrication oil.
Drain the excess oil from the oil pan.
- The engine misfires or the engine runs rough.
Refer to "The Engine Misfires or the Engine Runs Rough.".
- The fuel injection timing is not correct.
Adjust the timing of the fuel injection pump.
- The valve guides are worn.
Replace the valve guides. Check the flatness of the cylinder head. Recondition the cylinder head if the flatness is out of tolerance.
- The piston rings are worn.
Replace the piston rings.
- The engine consistently runs below the normal operating temperature. The water temperature regulator is faulty.
Replace the water temperature regulator.
The Engine has Low Oil Pressure
- The oil filter is restricted.
Install a new oil filter. Replace the lubricating oil in the engine with clean oil. Check the operation of the bypass valve for the filter.
- Fuel is in the lubricating oil.
Determine the source of the fuel. Refer to "The Engine has Early Wear.".
- Too much clearance exists between the bore of the rocker arm and the rocker shaft.
Check for adequate lubrication of the rocker arms. Replace parts which are worn.
- The suction pipe for the oil pump is faulty.
Replace the suction pipe.
- The engine oil bypass valve does not operate correctly.
Clean the bypass valve. Replace faulty parts.
- The oil pump does not operate correctly.
The oil pump must be repaired or replaced.
- Too much clearance exists between the crankshaft and the crankshaft bearings.
Replace the crankshaft or the crankshaft bearings.
- Too much clearance exists between the camshaft and the camshaft bearings.
Replace the camshaft or the camshaft bearings.
The Engine Uses Too Much Lubrication Oil.
- The engine contains too much lubrication oil.
Drain the excess oil from the oil pan.
- Oil lines have leaks.
Find the source of the oil leaks. Repair the line or fitting.
- The valve guides are worn.
Refer to "The Engine Exhaust has Too Much White Smoke or Blue Smoke.".
- The piston rings are worn.
Replace worn parts.
The Engine Coolant is Too Hot.
- The air flow through the radiator is restricted.
Clean the exterior of the radiator in order to remove all restrictions.
- The coolant level in the engine is low.
Add coolant into the radiator to the correct level.
- The pressure cap is faulty.
Test the operation of the pressure cap. Replace a faulty pressure cap.
- Gases from combustion are in the coolant.
Find the source of the entry of the gases from combustion into the coolant system. Repair the source of the problem.
- The water temperature regulator is faulty.
Test the water temperature regulator for correct operation. Replace a faulty water temperature regulator.
- The water pump is faulty.
The water pump must be repaired or replaced.
- The engine is operating with too much load.
Reduce the load.
- The timing of fuel injection pump is incorrect.
Adjust the timing.
The Starting Motor Does Not Turn or the Starting Motor Slowly Turns.
- The battery is discharged.
Charge the battery. Replace a faulty battery. Clean all cable terminals and battery posts. Apply the 1U-8267 Battery Saver and Cleaner on the cable clamps and the battery posts. Tighten the cable clamps on the battery posts.
- The terminals or the brushes of the starting motor have a short circuit to ground.
Find the short circuit. Repair the short circuit.
- The brushes of the starting motor do not seat against the commutator correctly.
The brushes are worn, broken, oily or dirty. The brushes must be cleaned or replaced. Clean the brush holders.
- The ignition switch, the starting motor solenoid, or the start relay is damaged.
Replace the ignition switch, the starting motor solenoid, or the start relay.
- An excessive voltage drop exists in the cables or across the terminals in the circuits for the starting motor. The cables are loose at the terminals, corroded, or cracked. The terminals are corroded or broken.
Inspect the cables and terminals for loose connections, corrosion or other damage.
The Starting Motor Turns, but the Pinion Gear Does Not Engage the Flywheel Ring Gear.
- The pinion drive or the overrunning clutch is faulty.
Replace the pinion drive or the overrunning clutch.
- The ring gear of the flywheel is damaged.
Replace the ring gear of the flywheel.
- The shift lever or the linkage is damaged.
Replace the shift lever or the linkage.
- The starting motor solenoid is damaged.
Replace the starting motor solenoid.
- The armature or idler gear of the starting motor is damaged.
Replace the armature or idler gear.
The Engine Does Not Crank or the Engine Rotates Slowly when the Keyswitch is in the Start Position.
- The battery has a low charge.
Refer to "The Starting Motor Does Not Turn or the Starting Motor Slowly Turns.".
- The brush pressure on the commutator of the starting motor is inadequate.
Check the tension of the spring for the brush. Refer to "The Starting Motor Does Not Turn or the Starting Motor Slowly Turns.".
- The start relay is faulty.
Replace the start relay.
- An excessive voltage drop exists in the cables or across the terminals in the circuits for the starting motor. The cables are loose at the terminals, corroded, or cracked. The terminals are corroded or broken.
Inspect the cables and terminals for loose connections, corrosion or other damage. Replace damaged parts.
- The overrunning clutch for the pinion drive slips.
Replace the overrunning clutch.
The Starting Motor Continues to Run After the Ignition Switch is Released.
- The ignition switch, the start relay, or the starting motor solenoid is faulty.
Replace the ignition switch, the start relay, or the starting motor solenoid.
The Pinion Gear Does Not Disengage After the Engine Starts to Run.
- The return spring of the pinion solenoid is damaged.
Replace the return spring of the pinion solenoid.
- The shift lever or the linkage is damaged.
Replace the shift lever or the linkage.
- The ignition switch or the start relay is faulty.
Replace the ignition switch or the start relay.
The Alternator Does Not Charge the Battery.
- The drive belt for the alternator is loose.
Inspect the drive belt for wear and damage. The drive belt must be adjusted or replaced.
- The drive pulley for the alternator is loose or worn.
Inspect the pulley for wear and damage. Tighten the nuts of the pulley to the correct torque. Replace a damaged pulley.
- The electrical cables and connections in the charging and starting circuits are loose or damaged.
Inspect all cables and connections. All connections must be clean and tight. Apply the 1U-8267 Battery Saver and Cleaner to the cable terminals and the connections. Replace damaged parts.
- The regulator or the field winding of the rotor in the alternator are faulty.
The alternator must be repaired or replaced.
The Alternator Charge Rate is Slow or the Alternator Charge Rate is Not Regular.
- The drive belt for the alternator is loose.
Inspect the drive belt for wear and damage. The drive belt must be adjusted or replaced.
- The drive pulley for the alternator is loose or worn.
Inspect the pulley for wear and damage. Tighten the nuts of the pulley to the correct torque. Replace a damaged pulley.
- The electrical cables and connections in the charging and starting circuits are loose or damaged.
Inspect all cables and connections. All connections must be clean and tight. Apply the 1U-8267 Battery Saver and Cleaner to the cable terminals and the connections. Replace damaged parts.
- The regulator or the rectifier for the alternator is faulty.
Replace the regulator or the rectifier.
- The brushes of the alternator are worn or dirty.
The brushes must be cleaned or replaced.
The Alternator Charges the Battery at a Voltage that is Too High.
- The alternator or the regulator has loose electrical connections.
Tighten all electrical connections to the alternator and the regulator.
- The regulator is faulty.
Replace the regulator.
- The drive belt for the alternator is worn or damaged.
Replace the drive belt for the alternator.
- The drive pulley for the alternator is loose or worn.
Inspect the pulley for wear and damage. Tighten the nuts of the pulley to the correct torque. Replace a damaged pulley.
- The drive belt and the drive pulley are not in alignment.
Adjust the alignment.
- The bearings of the alternator are worn or damaged.
Replace the bearings.