Mitsubishi 4D31T Troubleshooting
| Engine Model: Mitsubishi 4D31T |
| Engine Type: 4-cycle inline 4-cylinder turbocharged liquid-cooled diesel |
| Total Displacement: 201.3 cu.in (3.29 L) |
| Rated Engine Power: 82-130 Hp (62-96 kW) at 2100-3500 rpm |
| Fuel System Type: Direct injection |
____________________________________________________________________________________
| Engine hard to start or doesn't start |
Fuel filter element clogging - Replace filter element.
Air in fuel system - Bleed fuel system.
Fuel injection nozzles fault - Replace injection nozzles.
Damaged fuel injection pump - Change pump or rebuild it.
Improper valve timing - Adjust or replace timing gear.
Restricted fuel pipes - Clean or change fuel pipes.
Incorrect injection timing - Adjust as recommended.
Cylinder or piston rings are worn - Change faulty components.
| Diesel starts but immediately shuts off |
Fuel filter element is clogged - Change filter element.
Fuel injection pump failure - Replace or rebuild injection pump.
Air filter is dirty - Clean or replace the element.
Unadjusted nozzle opening pressure - Set up as recommended.
| Engine shuts off suddenly during operation |
Timing of fuel injection pump is incorrect - Adjust according to specifications.
Fuel filter element clogging - Service the filter.
Coolant temperature is low - Warm up engine as required.
Stuck or clogged injection nozzle - Service or change injection nozzles.
Low idle speed setting is incorrect - Correct low idle adjustment.
Valve clearance is not correct - Have it adjusted.
Fuel injection pump is not working correctly - Replace or rebuild injection pump.
Faulty or dirty injection nozzles - If necessary, replace with a new nozzle.
Clogged fuel lines or hoses - Clean fuel lines and hoses.
Dirty air cleaner - Clean air cleaner element.
Damaged cylinder-head gasket - Install a new gasket.
Injection timing is wrong - Adjust according to specifications.
Fuel injection pump is damaged - Replace injection pump or repair it.
One of moving engine components is worn - Replace or repair damaged components.
Radiator core is dirty or radiator cap is damaged - Clean radiator or change cap.
Coolant level is low - Add coolant fluid to cooling system and also check it for leaks.
Broken or loose fan belt - If necessary, replace the belt.
Insufficient engine oil - Check and refill engine oil.
Worn cylinder head gasket - Cylinder-head gasket replacement required.
Injection timing is improper - Set the injection timing correctly.
| Oil pressure is insufficient |
Low oil level - Add oil to the engine crankcase.
Oil pump failure - Replace as required.
Oil filter clogging - Change or clean engine oil filter element.
Stuck or worn relief valve - Change or clean relief valve.
Excessive oil clearance of crankshaft bearing - Test and replace or repair worn components.
Crankpin bearing clearance is excessive - Test and repair or replace worn parts.
| Engine oil consumption is too high |
Oil leakage: Damaged gaskets or seals - Replace defective parts.
Oil viscosity is wrong - Use proper viscosity oil.
Stuck or defective piston rings - Change piston rings.
Damaged valve stems or valve guides - Replace the valves.
Worn pistons or cylinder liners - Inspect liners and pistons, fit new parts as necessary.
| Abnormal engine knocking or noise |
Engine is cold - Warm up engine as required.
Engine oil level is insufficient - Fill up the engine oil.
Timing of fuel injection pump is incorrect - Adjust the pump as required.
Pistons are worn or scored - Pistons replacement required.
Connecting rod is misaligned or defective - Replace or align connecting rod.
Battery voltage is low - Charge the battery.
Battery runs out quickly - Battery needs service or replacement.
Disconnected battery cables or bad terminals - Connect wires properly or change terminals.
Battery is drained or worn - Charge or change the battery.
Wiring is improperly connected or disconnected - Check wiring and connect properly.
Battery voltage is low - Recharge the battery.
Starter motor failure - Starter needs to be replaced.
____________________________________________________________________________________
| Industrial Engines Technical Specifications |
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Outboard Engines Technical Specifications |
