Advice 1: How to check the spark

What to do and where to start if the engine won't start? Sometimes a philosophical question attends car owners.

First you need to determine the cause of failure. As a rule, to start the engine needs fuel, air and spark that will ignite the air-fuel mixture in the engine cylinders. If the air filter is in order and the mixture of fuel and air enters the intake manifold, it's time to check the ignition system. To test the spark alone can and should not delay this process "indefinitely", but rather to the visit to the station.

Verification is the following: with the help of candlestick key, you must remove the spark plugs from heads of cylinder blocks and carefully to see them. The first thing you need to pay attention to is the gap between the center and side electrodes. It needs to match the values from 0.7 to 0.9 mm. If the clearance is more, it is necessary to bend the side electrode if it is less to bend. Also pay attention to the condition of the candle: soot can also tell you about the operation of the engine. To check the spark Nagar should be removed using fine emery paper.

To conduct an audit independently, you can link all the candles are wired in series and the free end of the wire to ground to ground of the car, put on the plugs tips of high-voltage wires. Then, using the starter start to spin the engine and observe the spark between the electrodes. Its appearance and color also can be very telling. If spark is weak on all the candles or none at all, it is likely failed electronic switch. If the spark is there, but on all or on a candle, it is different, the problem may be the following:

  • the breakdown of the high voltage wire from the distributor to the spark;

  • runner distributor (distributor) has a defect or production;

  • faulty spark;

  • intermittent contact with the tip wire.

If you were able to candle light to check spark on their own and as a result of verification to establish that it is not possible at the same time to test and work the ignition coil. For this you need to install on one of the spark gap of 2-4 mm and crank the engine. If this spark sparks also is not, then the ignition coil is faulty. In cars with a carburetor engine it is enough to replace, whereas in cars with injector injection system must be inspected and electronic switch that can fail.

Advice 2: How to check for spark

Spark discharge is used in gasoline internal combustion engines. It occurs at the spark plug and ignites the air-petrol mixture in the cylinder. If engine does not start, in most cases, this is due to the malfunction of the high voltage wiring and the disappearance or weakness of sparks.
You will need
  • - candle key;
  • - a set of tools;
  • - brush for cleaning of candles;
  • - feeler gauge to check clearance.
Make sure that the problem is with the sparkle in the candlelight. To do this, remove the wire from any candle. Set its tip at a distance of 5-6 mm from any unpainted part of the engine (this is ground). When turning the starter between the wire and the weight should slip a powerful bluish spark. This means the problem is with candles. If it is not - the problem is in the electrical equipment of the vehicle.
Disconnect high-voltage wires from spark plugs. A special key (called the candlestick) remove all spark from the cylinder block. Coil them in a row uninsulated wire for the conductive part, which related to the cylinder block. The contact must be tight. The free part of the wire securely on the weight of the car. Can any part of the engine is not covered with paint or anti-corrosion composition. Again, put on the candles high-voltage wires.
Crank the engine with the starter. Normal spark should slip between the electrodes with a constant frequency and amplitude. It should have a purple color to be relatively thick (diameter must be visually comparable to the electrode diameter), clearly snapping at the discharge. This spark needs to be on each candle.
Thin threadlike spark tells about faulty ignition system. Carefully inspect the plugs. The electrodes can be covered with soot, melting or wet (covered with oil or fuel). Soak the plugs in kerosene and remove the carbon brush of copper wire. If the electrodes are damaged, replace the plug.
Special feeler gauge check the gap between the electrodes. It should be 0,8-0,95 mm. If it is more or less, bend the side electrode. Do it with a special key, this will keep the candle safe. Do not attempt to bend the Central electrode it will cause damage to the candles.
Poor spark on all four spark can be caused by a weak battery. Recharge it and check the electrolyte density. Very rarely the lack of spark can be caused by a faulty high voltage ignition coils. To see this, make the spark gap is about 4 mm. If the cranking of starter, a strong spark, replace the coil.
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