What happened to the engine jitter after the Roewe 350 changed the cylinder head?

The engine jitter of Roewe 350 after replacing the cylinder head may be caused by unclean throttle, uneven intake, poor oil circuit and abnormal gearbox operation. The most common cause of engine jitter is that the throttle valve is too dirty or the injector has too much carbon deposit. If there is too much carbon deposit in the engine, most of the gasoline sprayed by the injector will be absorbed by the carbon deposit during the cold start, which will make the mixer too thin and difficult to start. In this case, the gasoline adsorbed by carbon deposits can only hit the car in a saturated state, and the gasoline adsorbed on carbon deposits after hitting the car will be sucked into the cylinder by the vacuum suction of the engine for combustion, which will make the mixture rich and the combustible mixture of the engine dilute and unstable, resulting in engine jitter. Million car purchase subsidy