When the speed of a fire truck is unstable, the following positions should be checked first:
1. Oil system: If the fire truck has air leakage, blockage, poor circulation and other problems, it is basically a problem with the oil system. It will cause the speed of the fire truck to be unstable.
2. Fuel injection pump speed regulator: If the fuel injection pump speed regulator has a fault, the speed will not be stable, and the speed regulator inspection needs to be carried out professionally.
The following positions should be checked first when the fire truck engine overheats:
1. Cooling system: Fan damage, radiator blockage, thermostat damage, insufficient coolant, etc. will cause the engine to overheat.
2. Engine oil quality and oil quantity: If the engine oil quality is poor or the engine oil quantity is insufficient, it may also cause the engine to overheat.
3. Mechanical failures, such as cylinder flushing, cylinder liner or cylinder liner cracks, also have this phenomenon.
4. The injection advance angle is too small, resulting in an increase in afterburning (combustion in the exhaust pipe), and the fire truck will have an overheating phenomenon with the exhaust pipe burning red.
If the exhaust pipe is wet or dripping, the following should be checked:
1. Wear of the injection pump plunger and the oil outlet valve: The injection pump plunger and the oil outlet valve are seriously worn, and the pump oil pressure is insufficient, resulting in poor atomization of the injector, failure of individual cylinders to work, and oil dripping in the exhaust pipe.
2. Atomization of the injector: Oil dripping or poor atomization of the injector will cause abnormal operation of the cylinder when starting, and there may be oil dripping in the exhaust pipe.
3. Wear of the valve clearance and piston ring: Incorrect valve clearance or severe wear of the piston ring will reduce the cylinder compression pressure, causing individual cylinders to fail to work when starting, and the exhaust pipe may be wet or dripping.
4. Under normal circumstances, long-term operation at low temperature and low speed may also cause the exhaust pipe to be wet or dripping, but as long as the exhaust is no longer wet after working under load, it is a normal situation and no professional inspection of the fire truck is required.
