Interruptions in the engine

In case of interruptions, the engine runs unstable at idle, does not develop sufficient power, and consumes gasoline excessively. In addition, the failure of the exhaust gas converters is possible. Interruptions are usually due to a malfunction of the injectors or the electric fuel pump (see Engine management system), malfunction of the spark plug of one of the cylinders, air leakage into one of the cylinders. You need to find the problem and fix it if possible.



1. Start the engine and let it idle. Go to the exhaust pipe and listen to the sound of the exhaust. You can bring your hand to the cut of the exhaust pipe - so interruptions are felt better. The sound must be even «soft», one tone. Pops from the exhaust pipe at regular intervals indicate that one cylinder is not working due to the failure of the candle, the absence of a spark on it, the failure of the injector, a strong air leak into one cylinder or a significant decrease in compression in it. Popping at irregular intervals is due to dirty injector nozzles, heavy wear or dirty spark plugs. If pops occur at irregular intervals, you can try to replace the entire set of candles yourself, regardless of mileage and appearance, but it is better to do this after contacting a car service to diagnose and repair the engine control system.




2. If the pops are irregular, stop the engine and open the hood. Check the connection of the wiring harness block to the ignition module..



3.... and tightening the two module fixing screws.



4. If the wiring harness block is securely connected and the module mounting screws are tight, remove the module (see Removal and installation of the ignition module).




5. Remove the spark plugs (see Replacement and maintenance of spark plugs), carefully inspect the candles and compare their appearance with the photographs shown in the next subsection Diagnostics of the engine condition by the appearance of spark plugs. If the candle is black and damp, it can be discarded.

6. If all the candles look serviceable, install them in the tips of the ignition module, and screw spare candles into the candle holes in the block head.

7. Attach the wiring harness connector to the ignition module.



8. Attach the candle cases one by one, for example, with a wire to start the engine from an external current source to «mass» car (for example, to a wire connected to the negative battery terminal). Have an assistant turn the engine crankshaft with the starter.

Attention!

• Reliable contact of the candle body with «weight» is mandatory, since if an additional spark gap appears that is larger than the gap between the spark plug electrodes, the engine control unit or the high-voltage circuit of the ignition module may be damaged.
• Carry out the specified check for no more than five seconds, so that during the subsequent start-up, do not damage the exhaust gas converter by gasoline that has not burned out in the engine cylinders.

If any spark plug is missing, the spark plug may be faulty. To check, swap this candle in the module with a known-good one, on which there was a spark during the previous check. Repeat the test: if there is no spark and when installed in another tip of the module, the candle is faulty. If a spark appears on the candle, the ignition module is faulty, replace it.

If as a result of the measures taken engine interruptions are not eliminated, check the compression in each of the cylinders (see Cylinder compression check). Normal compression - more than 1.0 MPa (10 kgf/cm²), the difference is more than 0.1 MPa (1 kgf/cm²) in one cylinder indicates the need for engine repair.