When using the brake pedal, it is found that the pedal is heavy and the braking performance is poor, the working performance of the vacuum supercharger should be checked. The simple diagnostic methods are as follows.

　　①将发动机熄火，快速反复踏制动踏板，使制动踏板到高位置。起动发动机，如感到踏板稍微下降，则为真空制动增压器工作基本正常。如踏板无下降感觉，为真空制动增压器无助力作用，应检修或更换。

　　(1) Put out the engine and pedal the brake pedal quickly and repeatedly, so that the brake pedal reaches the highest position. Starting the engine, if the pedal is slightly lowered, the vacuum brake supercharger will work normally. If the pedal feels no drop, it should be repaired or replaced because the vacuum brake supercharger is powerless.

　　②起动发动机并运转I一2min，然后缓慢地踏几次制动踏板，每次踏下制动踏板有升高感觉时，为真空制动增压器密封良好。如制动踏板连续踏动仍不升高，则增压器动力缸的密封不良，应检查或更换。

　　(2) Start the engine and run for 1-2 minutes, then slowly tread the brake pedal several times, each time the brake pedal feels elevated, the vacuum brake supercharger is well sealed. If the brake pedal continues to tread and does not rise, the seal of the power cylinder of the supercharger is not good and should be checked or replaced.

　　③在发动机运转情况下，用脚踏下制动踏板并将发动机熄火，如30s左右制动踏板位置不发生变化，为真空制动增压器密封良好。如制动踏板位置很快变动，为密封不良，应检修或更换。

　　(3) When the engine is running, the brake pedal is lowered by foot and the engine is extinguished. If the position of the brake pedal is unchanged about 30 seconds, the vacuum brake supercharger is well sealed. If the position of the brake pedal changes quickly, it should be repaired or replaced for poor sealing.

　　用上述方法检查真空增压器，虽然不能准确地判断发生故障的部位，但可以掌握其工作,性能。

　　Using the above method to inspect the vacuum supercharger can not accurately determine the fault location, but can grasp its work and performance.

　　断油控制分为急减速断油、超速断油和清缸断油，目的是节油、降低排放污染，确保汽车行驶和提高发动机的起动性能。

　　Oil cut-off control is divided into rapid deceleration oil cut-off, overspeed oil cut-off and cylinder clean-up oil cut-off. The purpose is to save fuel, reduce emission pollution, ensure vehicle driving safety and improve engine starting performance.

　　1、急减速断油在发动机怠速运转冷却液温度正常后，用导线短接TPS插接器（于4端子插接器）上的IDL和E1端子（即让怠速触点闭合），然后踩下加速踏板，使发动机转速达到1800r/min，这时发动机转速应会突然下降到1200r/min；稳住加速踏板的位置，发动机转速应在1200一1800r/min之间周期性地变化。如果不出现上述情况，说明TPS怠速触点或ECU相关电路有故障。

　　1. After the engine idles until the coolant temperature is normal, the IDL and E1 terminals (i.e. the idle contacts are closed) on the TPS connector (limited to the 4-terminal connector) are connected with short conductors, and then the acceleration pedal is pressed down to make the engine speed reach 1800 r/min. At this time, the engine speed should suddenly drop to 1200 r/min; at the same time, the position of the acceleration pedal should be stabilized, the engine speed should be adjusted. It varies periodically from 1200 to 1800 r/min. If the above situation does not occur, it indicates that TPS idle contacts or ECU related circuits are faulty.

　　2、超速断油超速断油的作用是限制发动机的高转速（6500r/min )。超速断油控制性能的检查方法是，拆下1只喷油器线束侧插接器，然后在将加速踏板踩到底时起动发动机，同时用万用表（20V档）检查喷油器线束侧插接器两端子间是否有脉冲电压。此时应无脉冲电压，否则TPS或ECU相关电路有故障。

　　2. The effect of over-speed oil cut-off and over-speed oil cut-off is to limit the maximum speed of the engine (6500r/min). The method to check the control performance of over-speed fuel cut-off is to remove one injector wiring harness side connector, then start the engine when the accelerator pedal is pushed to the bottom, and check whether there is a pulse voltage between the two terminals of injector wiring harness side connector with a multimeter (20V gear). At this time, there should be no pulse voltage, otherwise TPS or ECU related circuits have faults.

　　3、清缸断油清缸断油用于在发动机多次起动不着后气缸内的燃油，其检查方法与超速断油相同。

　　3. Cylinder clearance, cylinder clearance and cylinder clearance are used to clean the fuel in the cylinder after the engine fails to start many times. The inspection method is the same as that of over-speed oil breakage.