In 2009, there was air leakage in the intake pipe on the Lefeng engine.

Air leakage in the intake manifold. In 2009, Lefeng engine should inhale air when doing work. After the air passes through the throttle body, different pressures will be formed in the intake manifold according to the different intake volume. When the pressure is too high, the intake manifold will leak air, resulting in insufficient air (oxygen) required for combustion in the cylinder, insufficient combustion, poor mixing ratio, unable to accelerate, and will tremble in severe cases. This situation should be repaired in time.