There Are Three Ways To Check The Ignition Coil

　　The first is the comparative method, that is, after replacing the ignition coil with a new one, the fault will be eliminated and the engine is working normally, indicating that the ignition coil is damaged. The second type is to use a multimeter to measure the resistance of the low-voltage coil and the high-voltage coil of the ignition coil. The value of the low-voltage coil is about 1 ohm, and the value of the high-voltage coil is about 5,000 ohms, which is normal. If the resistance value is too small, it means that the ignition coil may be short-circuited; if the coil is blocked, it means that the ignition coil is open.

　　The third type is to check with a 220-volt alternating current. Connect a 25-watt bulb in a 220-volt circuit as a test light, and use two insulated contact pins to contact the positive and negative terminals of the low-voltage coil of the ignition coil respectively. If the test light is on, Indicating that the low-voltage coil is good; if the test light does not light up, it is a circuit breaker. Use an insulated contact pin to contact the shell of the ignition coil. If the test light is not on, it means that the insulation is good; if the test light is on, it means that the low-voltage coil is short-circuited. Then check the high-voltage coil, and contact an insulated contact pin with the negative pole of the low-voltage coil. If the test lamp does not light up and a small spark is generated on the low-voltage coil terminal, it indicates that the high-voltage coil is in good condition. The low-voltage coil terminal does not produce sparks, indicating that the high-voltage coil is open; if the test light is on, it indicates that the high-voltage coil is short-circuited.

　　Comprehensive fault diagnosis of high and low voltage circuits: After the above inspection and diagnosis, it is confirmed that there is no fault in the low voltage and high voltage circuits, and then focus on checking the working condition of the breaker. For example, whether the wiring of the movable contact is firm; whether the insulation between the insulating gasket and the fixed shaft of the movable contact is normal; whether the bakelite top block on the movable contact is worn, and whether the two contacts can be separated correctly on time; the movable contact spring sheet Whether the elasticity is weakened; whether the cam of the breaker is worn and affects the normal opening and closing of the contacts; whether the contacts of the breaker are ablated or stained with oil. If the contacts of the breaker are stained with oil, wipe them clean with tissue paper. If the contacts of the breaker are burnt, they should be ground. After the above inspection, it is found that there is no abnormal phenomenon, then turn on the power switch, rotate the engine, and check whether there is a strong spark between the contacts of the breaker. If the spark is very strong, it means that the capacitor may be damaged.

　　There are three ways to check capacitors: the first is the comparison method, that is, after replacing a good capacitor, the fault is eliminated and the engine is working normally, indicating that the original capacitor is damaged. The second is to check with 220-volt alternating current, connecting a 25-watt bulb in series with a 220-volt circuit. Use an insulated contact pin to contact the terminal of the capacitor, and then use another insulated contact pin to contact the metal shell of the capacitor. When the bulb is not bright or the bulb emits a very dark red light, the insulated contact pin should be removed, and the wiring of the capacitor should be in contact with the capacitor metal shell. If there is a strong blue spark discharge, it means the capacitor is in good condition; if there is only a faint spark or a sound of discharge, it means the capacitor is leaking; if there is no discharge at all, it means that the capacitor is off and the circuit is high; if the bulb lights up normally, It means that the capacitor is short-circuited. When using the above method to check, you must pay attention to safety, the bulb must be installed on the lamp socket, and the insulated contact pin must be insulated. At the same time, after the capacitor is charged, do not touch it directly with your hands to prevent the capacitor from discharging and hurting people.

　　The third type is an inspection on the vehicle, that is, two wires are drawn out from the two terminals of the battery, one of which is connected to the terminal of the capacitor, and the other is in contact with the metal shell of the capacitor. If there is a spark, it means that the capacitor is damaged. If there is no spark, connect the capacitor wire to the capacitor metal shell. If there is a spark discharge, the capacitor is in good condition; if there is no discharge, the capacitor is open. After the above diagnosis check, if it is determined that the ignition system is normal but the engine cannot be started, the fuel supply system should be checked.

　　The main reason for the failure of the combustible mixture to enter the cylinder is the blockage of the oil circuit. Examining the removed spark plug, it is found that the surface is dry. The gas discharged from the spark plug hole when the engine is turned by foot is dry and tasteless. When a small amount of fuel is dripped into the cylinder, the engine can be started again, but the engine will be turned off after a short time of operation. , Which shows that the oil circuit is blocked and the combustible mixture fails to enter the cylinder. At this time, you should unplug the fuel pipe to check whether there is a fuel supply. If there is no fuel supply, check whether there is fuel in the fuel tank.

　　If there is fuel in the fuel tank, check whether the small holes on the fuel tank cap, the throttle switch, and the fuel filter are blocked. If there is a fuel supply in the oil pipeline, the carburetor should be removed for cleaning, and the oil holes and air passages should be dredged to thoroughly remove sediment, impurities, rust, and other sundries. After cleaning, use a pump to blow the holes clean, and then start the test. The test proves that the combustible mixture has entered the cylinder, but the engine still cannot be started, check whether the cylinder compression pressure is sufficient, because when the cylinder compression pressure is insufficient, the engine cannot be started.