3.4. Interruptions in operation of the engine

Diagnostics of a condition of the engine on appearance of spark plugs

At interruptions the engine unevenly idles, does not develop sufficient power, is raised spends gasoline. Interruptions, as a rule, are explained by malfunction of nozzles or an electrogasoline pump, see. "Power supply system"; "An electronic control system of the engine (system of injection of fuel)", spark plugs of one of cylinders, an air suction in one of cylinders. It is necessary to find malfunction and whenever possible to eliminate it.
1. Launch the engine and leave it to idle. Approach an exhaust pipe and listen to an exhaust sound. It is possible to bring a hand to a cut of an exhaust pipe — so interruptions are felt better. The sound has to be equal, "soft", one tone. Cottons from an exhaust pipe through regular periods demonstrate that one cylinder does not work because of failure of a candle, lack of a spark at it, about refusal of a nozzle, about a strong suction of air in one cylinder or considerable decrease in a compression in it. Cottons through irregular periods arise because of pollution of sprays of nozzles, strong wear or pollution of spark plugs. If cottons occur through unequal periods, it is possible to try to replace independently all set of candles irrespective of a run and appearance, however it is better to do it after the address on car service for diagnostics and repair of a control system of the engine.
2. If cottons are regular, stop the engine and open a cowl. Check a condition of a plait of wires of system of ignition and fastening of blocks of wires on ignition coils. If there are damages of wires, replace all plait of wires of system of ignition.
3. Turn out spark plugs (see. "Replacement and service of spark plugs").
4. Attentively examine candles and compare their appearance to the provided photos in the subsection "Diagnostics of a Condition of the Engine on Appearance of Spark Plugs".
5. If all candles look serviceable...
6.... check a gap between candle electrodes (only round probe). It has to be 1,00–1,13 mm.
7. If the gap differs from specified, adjust its subflexible a side electrode.
8. Establish candles and coils into place and connect to them blocks of a plait of wires.
9. Disconnect a block of a plait of wires from the coil of the 1st cylinder. Launch the engine. If interruptions of the engine amplified, replace a candle in the 1st cylinder obviously serviceable. Put on a high-voltage wire and launch the engine. If interruptions amplified, consistently repeat the procedure with all cylinders to reveal a faulty candle.
If as a result of the taken measures interruptions of the engine are not eliminated, check a compression in each of cylinders (see. "Check of a compression in cylinders"). The normal compression — more than 1,0 MPas (10 kgfs/cm2), a difference of values of a compression in cylinders more than 0,2 MPas (2 kgfs/cm2) testifies to need of repair of the engine.