Application of automobile vacuum gauge

Some imported cars are equipped with vacuum meters, which can show the vacuum degree of the intake manifold, so that drivers can know the operation of the engine in time. The indicating unit of vacuum gauge is usually inches of mercury. When idling, the pointer of normal vacuum gauge should be 8 ~ 16 inch Hg, and the pointer is basically stable. If the pointer swings violently. Explain that the ignition circuit and valve mechanism are faulty; If the pointer indicates too low, it is an inaccurate ignition time or a poor seal of the valve train. When the engine accelerates, the pointer swings too much, which is generally caused by poor cylinder seal.