What happened to the dull engine of the Land Cruiser 4700 in 2002?

There are many reasons why the horsepower is not enough to work, which involve the compression state of crank-connecting rod mechanism, whether the valve is closed tightly, the technical state of lubrication and cooling system and so on. The following is a brief description of the supply system: \r\n 1 Indications \r\nThe engine is jammed, the speed drops, black smoke is emitted, some cylinders knock, the engine is unstable, the vibration is high, and the engine is overheated. Due to different reasons, the performance is not exactly the same. \r\n2 Cause analysis \r\n2. 1 Insufficient oil supply. The oil return control valve in the oil circuit of the pump cover is not closed properly, and the engine is unstable at this time. In severe cases, it will turn off with a little load, making it difficult to start. \r\n2.2 The oil circuit leaks oil, and the air intake or fuel filter is blocked, so that the oil intake is not smooth and the engine cannot work. \r\n2.3 The copper gasket of the oil outlet valve is broken and leaks oil; The oil outlet valve is not closed properly; The spring of the oil outlet valve is broken, which leads to the decrease of oil supply and engine weakness. \r\n2.4 The plunger pair is worn, and the oil supply is insufficient, which is often accompanied by difficult starting and unstable operation when the throttle is small. In addition, the plunger or roller moves slowly, and the elasticity of the plunger spring is too weak, which also affects the oil supply and makes the engine unable to work. \r\n2.5 Loose plunger adjusting arm, broken plunger spring or loose adjusting fork on fuel supply pull rod will also affect fuel supply and make the engine fail. \r\n2.6 The fuel injector leaks oil or the nozzle hole is blocked, resulting in poor atomization quality, poor combustion after fuel injection, engine weakness, knocking sound and black smoke from the exhaust pipe. \r\n2.7 The fuel supply advance angle is incorrect. \r\n2.8 The air filter is blocked, and the amount of air sucked into the cylinder is insufficient, resulting in incomplete combustion, and the engine emits black smoke and is weak. \r\n2.9 The oil supply of the oil transfer pump is insufficient. \r\n2. 10 The exhaust pipe is blocked, which affects the exhaust gas. After the exhaust, the pressure in the cylinder is high, which affects the intake of fresh gas, and the combustion is not good after fuel injection. \r\n3 Prevention and elimination \r\n3. 1 Remove the pump cover oil return pipe connector and check the sealing condition of the oil return control valve. \r\n3.2 Clean the primary and secondary fuel filters, dredge the blocked oil circuit, find out the oil circuit leakage and eliminate it. \r\n3.3 Replace the damaged copper gasket of the oil outlet valve. The oil outlet valve is not tightly closed, so it can be ground with engine oil. \r\n3.4 The plunger pair is badly worn and should be replaced. \r\n3.5 Fix the loosening activity of the plunger adjusting arm and tighten the loosening state of the adjusting fork on the oil supply pull rod. \r\n3.6 Re-adjust the cable length of the rocker arm that stops oil supply. \r\n3.7 Check the atomization quality of the fuel injector and adjust the injection pressure. \r\n3.8 Re-adjust the fuel supply advance angle or replace related parts. \r\n3.9 Clean the air filter, but when reinstalling it after cleaning, please install the rubber sealing ring correctly and add a proper amount of oil in the oil pan. \r\n3. 10 Find out the reason of insufficient oil supply of the oil transfer pump and eliminate it. \r\n3. 1 1 Remove carbon deposits in the exhaust pipe and combustion chamber.