Spark discharge is used in gasoline internal combustion engines. It originates in the spark plug and ignites the air / gasoline mixture in the cylinder. If the engine does not start, in most cases this is due to a malfunction of the high-voltage wiring and the disappearance or weakness of the spark.
Necessary
- - candle key;
- - set of tools;
- - brush for cleaning candles;
- - dipsticks for checking the gap.
Instructions
Step 1
Make sure the spark is in the spark plugs. To do this, remove the wire from any candle. Install its tip at a distance of 5-6 mm from any unpainted part of the engine (this will be the mass). When cranking the starter, a powerful bluish spark should jump between the wire and ground. This means there is a problem with candles. If it is not there, the problem is in the electrical equipment of the car.
Step 2
Disconnect the high voltage wires from the spark plugs. Unscrew all the candles from the cylinder block with a special wrench (it is called a spark plug). Wrap them in one row with bare wire over the conductive parts that touched the cylinder block. The contact must be tight. Fasten the free part of the wire securely to the ground of the vehicle. It can be any part of the engine that is not covered with paint or anti-corrosion compound. Reattach the high-voltage wires to the spark plugs.
Step 3
Crank the engine with a starter. A normal spark should jump between the electrodes of the candle with a constant frequency and amplitude. It should have a violet color, be relatively thick (the diameter should be visually comparable to the diameter of the electrode), and clearly click during the discharge. This spark should be on every candle.
Step 4
A thin thread-like spark indicates a malfunction of the ignition system. Examine the candles carefully. The electrodes can be carbonated, melted, or wet (covered with oil or fuel). Soak candles in kerosene and remove carbon deposits with a copper wire brush. If the electrodes are damaged, replace the spark plug.
Step 5
Check the electrode gap with a special feeler gauge. It should be 0.8-0.95 mm. If it is larger or smaller, bend the side electrode. Use a special key to keep the candle intact. Do not try to bend the center electrode as this will damage the spark plug.
Step 6
A bad spark on all four spark plugs can be caused by a weak battery. Recharge it and check the density of the electrolyte. Very rarely, the absence of a spark can be caused by a malfunction of the high voltage ignition coil. To verify this, make a gap of about 4 mm on the candle. If there is no strong spark when cranking the starter, replace the coil.
