A car's ignition system consists of a battery, a generator, a distributor, an ignition coil and a spark plug. It can provide sufficient voltage at the appropriate time, so that the spark plug can generate enough sparks to ignite. the mixture in the cylinder, allowing the engine to achieve optimal combustion efficiency. It can be said that the ignition system of a car plays an irreplaceable role in the use of the car. So this article mainly takes you to understand the common faults and repair methods of the car ignition system and how to maintain the car ignition system. Follow the editor to learn more.
Common automotive ignition system fault diagnosis
1. How to adjust the ignition timing of the traditional ignition system?
No timing lamp adjustment method
① Firstly, adjustSet the contact gap of the distributor to the appropriate value as required.
② Find the position of the top dead center of compression of the first cylinder. Remove the high voltage bypass line from cylinder 1. Remove the No. 1 spark plug with a spark plug sleeve, plug the spark plug hole with your thumb or a piece of cloth, and then shake the engine crankshaft. When you feel resistance in the cylinder, slowly turn the crankshaft and watch to align the timing mark.
③ After the above parts meet the requirements, turn on the ignition switch, loosen the distributor housing fixing screw, and turn the distributor housing to close the circuit breaker contacts. Then rotate the distributor in the opposite direction until the distributor contacts barely open. At this time you can see a small spark generated between the contacts. Then tighten the housing mounting screwsof the distributor and adjust the octane number to the scale of. The zero position; At this time, the direction pointed by the burner head is the position of cylinder 1.
④ Connect the high voltage branch wire to the distributor cover according to the ignition sequence, tighten the screws to hand and temporarily secure the dispenser.
⑤ Start the engine and check the ignition timing. If the engine ignition system and fuel supply system are well adjusted at this time, the engine exhaust pipe should drip water and the engine vibration and noise should be minimized. .
Timing light adjustment method
① Start the engine and warm it up to normal operating temperature.
② Connect the two black clips of the ignition timing light to the positive and negative terminals of the battery respectively, and attach the sensor to the high voltage wire of the first cylinder.
③ Adjust the engine speed to normal idle speed, use the ignition timing light to illuminate the timing pulley, and check whether the mark on the pulley is at the angle specified by the manufacturer (usually 6° to 10 °).
④ If adjustment is necessary, loosen the distributor screw, use the ignition timing to align the timing pulley, then turn the distributor (left and right) until the mark scale is at the specified value, and finally tighten. the Can distributor screw.
2. What are common faults that occur when spark plugs are used?
Severe ablation of the spark plug
Scarring or damage on the top of the spark plug or melting or ablation of the electrode indicates that the Spark plug has been damaged and needs to be replaced. When replacing, signs of ablation and color changes should be checked for ananalyze the cause of the failure.
① The electrode melts and the insulation turns white. Indicates that the temperature in the combustion chamber is too high, This may be due to excessive carbon deposits in the combustion chamber, resulting in too little valve clearance, overheating of the exhaust valve, or poor operation of the cooling device. The spark plug may also not be tightened to the specified level. couple, etc.
② The electrode becomes rounded and the insulation becomes scarred. This indicates that the engine is pre-igniting, which may be due to premature ignition timing, low gasoline octane, or excessive spark plug heating value.
③ The top of the insulation is broken. Combustion by detonation is the main cause of insulation breakdown. Premature ignition timing, low gasoline octane, and excessive engine temperatureCombustion amber can cause engine knocking and burning.
④ There are gray and black stripes on the top of the insulation. This strip indicates that the spark plug is leaking and needs to be replaced with a new one.
Signal plugs have deposits
Deposits sometimes stick to the top of the spark plug insulator and between the electrodes. In severe cases, the engine may not work. Cleaning the spark plugs may be temporary. remedy the problem. To maintain good performance, the source of the problem must be identified.
① Oily sediment. Oily deposits on the spark plug indicate that lubricating oil has entered the combustion chamber. If it's just a few spark plugs, the valve stem oil seal may be damaged. If the spark plugs of each cylinder are stuck with this type of deposit, it indicates an oil leak in the cylinderdre, and the air filter and ventilation device should be checked to see if they are clogged.
② Black sediment. There are black deposits on the electrodes and inside the spark plugs, indicating that the mixture is too rich. You can increase the engine speed and continue for a few minutes to burn off the layer of black soot left on the electrodes.
3. How to repair the low voltage circuit failure of the ignition system?
① The horn sounds and the headlights come on. Use a screwdriver or wire to test for fire on the "-" terminal of the ignition coil. If there is no fire, there is an open circuit between the low voltage terminal of the ignition coil and the ammeter.
Test the fire in the following order: ignition coil "switch" → ignition coil "switch - power" terminal → ignition switch → ammeter, and diagnose the fire open circuit fault locationdepending on whether there is a fire or not. If the connection between the terminal and the wire is not secure or the contact is poor, clean the terminal and tighten the retaining nut. If a section of wire is broken, replace the section of wire and the replaced wire must have the same specifications; like the original thread.
② The horn does not sound and the headlights do not light up when turned on. Use a wire to test for fire at the starter terminal. If there is a fire, the fault is an open circuit between the starter terminal and the ammeter; if there is no fire, the fault is insufficient battery power or circuit failure. The battery is low and needs to be recharged; the circuit is disconnected and must be reconnected.
③ Use a screwdriver to test the fire on the “-” terminal of the ignition coil. If there is a fire, test for fire between the distributor's moving contact arm and the base plate. If there is a fire, it isa contact fault (such as contact removal, too dirty, impossible to close, etc.). You can use "platinum sand strips" to grind the contacts and adjust the contact gap to eliminate the fault; If there is no fire, proceed to the next step.
④ Test for fire at the distributor insulating terminal and distributor shell. If there is no fire, it is an open circuit fault in the wire between the distributor insulating terminal and the "-". ignition coil terminal; if there is a fire, then it is absolutely There is an open circuit fault in the wire between the edge support and the insulating pole.
In the event of a power failure due to poor contact between terminals and wires, the terminals and wire heads should be cleaned and tightened. If a section of wire is broken, simply replace the section of wire with; a wire of the same specification.
4. How to repair h circuit failurehigh voltage of the ignition system?
① Remove the high voltage wire in the middle of the distributor cover, use a screwdriver to insert the high voltage wire post, hold the wooden handle or rubber handle, use the metal rod of the screwdriver to approach the raised iron part of the engine, then start. Check the engine to see if there is a spark. When starting the engine, if you find striking and strong sparks, this can prove that the high voltage circuit of the ignition system is good at least for the distribution board.
② If the spark is strong but the engine cannot start, it may be due to a problem with the spark plug or incorrect ignition timing. At this time, the spark plugs of each cylinder can be removed in turn and inspected in sequence.
③ If there is no spark jumping or dark red stars are flashing, replace the spark pluge ignition or wipe it to resolve the problem.
④ If you have a multimeter, you can clamp both ends of the high voltage cable and measure the resistance. If it is found to exceed 2.5×104Ω, the cable must be replaced.
⑤ If there is no problem with the high voltage line test, then the problem of no sparking lies in the distributor cover and the distributor cover. You need to check if these two parts are stained or broken. , or damaged. Leakage and other phenomena. If so, repair or update it.
5. What causes low flashover at high voltage? How to exclude it?
When the engine is running at high, medium and low speeds, the muffler makes a rhythmless "hissing" noise, or even trips, and the intake manifold sometimes backfires; the engine stalls easily and is difficult to start. which indicates that the sparks aregenerated under high pressure.
The reason for this fault
① The circuit breaker contact is removed.
② Bad internal contact or poor grounding of the capacitor.
③ The turns of the low voltage ignition coil are short-circuited.
Troubleshooting
First remove the high voltage distribution wire, about 5mm from the spark plug, and check the spark situation. If the spark jump distance is short and thin, the sound is small and red, and sometimes there is misfire phenomenon, this is a high voltage low spark fault. When checking the spark, it should be noted that the distance between the high voltage ignition wire and the spark plug should be compared from far to near or from near to far to avoid misjudgment caused by no spark due to long distance or weak spark due to short distance.
If the fire in the center linethe high voltage is weak, not a thick blue fire, but a **thin fire, you need to remove the capacitor and try again. Once the capacitor is removed, the spark remains unchanged and the fault lies in the capacitor; once the capacitor is removed the spark is weaker and the fault lies in the ignition coil. Then repair or replace the capacitor or ignition coil depending on the specific fault.