Knock sensor. Adjusting detonation
Detonation combustion occurs because of too early ignition timing. Long detonation can cause serious damage to internal engine parts. However, in today's automotive industry is constantly trying to bring as close as possible to the point of ignition "early ignition". Ignition system provides damping detonation by adjusting ignition timing. It allows you to use the maximum ignition timing in the absence of detonation, thereby ensuring good driveability and low fuel consumption. To detect detonation system has an electric knock sensor (one - for the 2.0-liter or two - engine VR6), which is screwed into the bottom of the cylinder block and constantly monitors the combustion process in the cylinders and cylinder records the appearance of "knock" . When the irregular beats sensor (or sensors) inform the control unit, which performs the following:
- Immediately determines which cylinder detonation occurred and sets the ignition it about 3 ?° later, leaving the amount of spark advance for the other cylinders of the former;
- The rest of the cylinders remain the same ignition timing and ignition timing "guilty" of the cylinder is delayed by about 3 ?°.
- If the detonating cylinder persists detonation combustion, the ignition timing control unit retards further 3 ?°. This process can occur several times in the subsequent working stroke of the cylinder;
- Only after detonating cylinder will continue to operate stably, the ignition timing after some time exhibited at earlier - in each cycle of the engine, at approximately 0.5 ?°, as long as there is no initial set again gradually ignition timing .
Meanwhile, the flow of information about the possible knock in the other cylinders.