Top of the list: low fuel pressure. Find out if there is fuel in the fuel tank. Check the fuel supply line between the fuel tank and the oil pump for leaks or recesses. Check for air entering the fuel system. The fuel control valve is stuck, stuck or failed. Check fuel pressure. When the engine is working at full load, the fuel delivery pump outlet pressure should be at least 415 kPa. If the fuel pressure is lower than the above pressure, the fuel filter element should be replaced. When the oil pressure is still low, you need to check the fuel pump.

Second: the valve clearance is incorrect. Adjust the valve clearance.

Third: poor fuel quality. Discharge the fuel in the fuel tank and replace the fuel filter. Add high quality fuel to the tank.

Fourth: The power setting is too low. Adjust engine power according to skill specifications on the engine brand.

Fifth: turbocharger carbon deposits. Look at the turbocharger and repair if necessary.

Sixth: View intake manifold pressure. Check that the air filter has a blockage.

Seventh: The air filter is blocked.