点火正时正确与否直接关系到发动机的动力性、经济性和有关机件的使用寿命。以往对于点火正时的调整,大部分驾驶和维修人员都习惯于仅凭感觉调整,造成点火时早时晚。这对于压缩比较小,发动机转速相对较低的解放CA10B型等汽车而言,虽然对发动机动力性、经济性有一定影响,但一般情况下(只要不是过早)不易引起发动机爆燃,还是可以勉强使用的。而对于新型汽车却是不可取的。因为现代汽车发动机为提高其功力性和经济性,其压缩比和发动机转速都大幅度提高(压缩比一般都在7.0以上,最高转速也都超过300r/min)。如果点火正时不准,不仅对发动机动力性和经济性影响很大,而且往往导致发动机爆震,造成活塞烧顶和断环等机械事故。正因为如此,各生产厂家对点火正时的调整要求都十分严格,一般都有明确的规定和具体的校对方法。必要时也可采用下述方法调整:取一只真空表将其用软管与进气歧管相连接,起动发动机并固定在某一稳定转速,松开分电器外壳固定装置,一边转动分电器外壳,一边观察真空表的指针,在 Ignition timing is correct or not directly related to the engine’s power, economy and the service life of the parts. In the past for the ignition timing adjustment, most of the driving and maintenance personnel are accustomed to adjusting the feeling alone, resulting in early night when the ignition. This for the compression ratio is relatively small, the engine speed is relatively low CA10B-type cars, although the engine power, economy has an impact, but under normal circumstances (as long as not too early) is not easy to cause the engine deflagration, or can barely in use. But for the new car is not desirable. Because modern car engines to improve their work and economy, the compression ratio and engine speed are greatly improved (compression ratio are generally above 7.0, the maximum speed are also more than 300r / min). If the ignition timing is not allowed, not only on the engine power and economy greatly affected, and often lead to engine knock, resulting in piston burning top and broken ring and other mechanical accidents. Because of this, the manufacturers of ignition timing adjustment requirements are very strict, generally have a clear provision and specific proofreading methods. If necessary, the following methods can also be adjusted: Take a vacuum gauge will be connected with the intake manifold with a hose, start the engine and fixed at a stable speed, loosen the distributor housing fixtures, while turning the distributor Shell, while observing the vacuum gauge pointer, at