The starting device functions normally, but the engine is difficult to start or cannot be started despite repeated attempts to start it according to the correct steps and methods. The exhaust pipe emits no smoke at all, or only a small amount of smoke; sometimes white smoke is emitted from the exhaust pipe, or smoke is emitted only initially and then stops.
(I) Fuel Supply System Failure
1. The diesel tank switch is not open, or the diesel tank is empty or has too little fuel.
Troubleshooting: Open the diesel tank switch, add enough diesel fuel, and purge air from the fuel lines.
2. The vent hole on the diesel tank cap is blocked, causing difficulty in fuel supply.
Troubleshooting: Clean the fuel tank cap and blow out the vent hole.
3. Low temperature results in high diesel viscosity and difficulty in flow.
Troubleshooting: Use diesel fuel that meets the operating requirements.
4. Impurities or frozen water in the diesel fuel cause the switch, fuel lines, and filter to not supply fuel.
Troubleshooting: Loosen the vent screw on the filter; if no fuel overflows, the fuel line is blocked. The diesel tank and filter should be cleaned. 5. Air is being drawn into the low-pressure fuel line due to a leak.
Solution: Locate the problem area and purge the air from the fuel line.
6. The high-pressure fuel line joint is not tight, the nut is loose, the contact surface between the delivery valve seat and the plunger sleeve is not tight, or the delivery valve seat is not tightened. It could also be due to worn-out gaskets.
Solution: Tighten all loose parts or replace the gaskets.
7. Water in the diesel fuel causes the plunger assembly to seize, the plunger spring to break, or the plunger assembly to be severely worn.
Solution: Repair or replace a seized plunger assembly, and replace the diesel fuel. If the injection pump does not pump fuel, it indicates a seized plunger, a broken spring, or a broken delivery valve, which should be cleaned or replaced immediately.
8. The delivery valve is clogged with impurities, the delivery valve spring is broken, or the delivery valve assembly is severely worn.
Solution: Check the operation of the injection pump. If the start and end times of the oil pump are unstable, the delivery valve may be faulty and should be cleaned or replaced.
9. Severe wear or seizing of the injector assembly, or a broken injector pressure regulating spring.
Solution: Clean or replace.
10. Injection pressure too high.
Solution: Readjust to the specified pressure.
11. Incorrect fuel injection timing.
Solution: Check and adjust the fuel injection advance angle.
12. Incorrect timing gear installation.
Solution: Readjust.
(II) Compression System Faults
1. Incorrect valve clearance.
Solution: Readjust.
2. Poor cylinder compression.
Solution: Grind the valves, check and adjust the valve clearance, and check the valve spring tension. If the piston, piston rings, or cylinder are worn, add a small amount of engine oil to start the engine. If the piston rings are stuck, misaligned, or broken, clean, correctly install, or replace them with new ones.
(III) Intake System Faults
Air filter or intake manifold blockage. Troubleshooting methods: Clean the air filter, replace or clean the filter element, and clear any blockages in the intake pipe.
