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Electric Motor
The control system of detonation combustion models with turbocharged The causes of detonation combustion of fuel is too early ignition and engine running on fuel with a low octane number. Detonation occurs when the rate of flame propagation in the combustion chamber approaches the speed of sound mainly by the end of the combustion process, the residual gases are highly compressed and heat. Detonation is characterized by a very high pulse pressure, which leads to the engine overheating, damage to the piston, cylinder head and the crankshaft bearing shells. However, when the engine is running at maximum load moment of ignition should be removed to the maximum without crossing the border early detonation combustion of fuel.
| Fig. 15.49. Elements of control detonation combustion vehicles 1986 and 1987 model years: 1 - the ignition coil; 2 - the ignition distributor; 3 - control unit; 4 - diagnostic connector; 5 - knock sensor; 6 - the block of management of ignition
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The control system consists of detonation combustion of fuel from the knock sensor, control unit and the ignition timing control unit EGI (Fig. 15.49). Knock sensor responds to emerging high-frequency oscillations in the detonation of the cylinder and transforms them into electric signals to the control unit. This information is then compared with the signals obtained during the combustion without detonation. When detonation occurs the ignition timing is shifted to the delay side by 6 ?�. When the frequency of engine speed 1650-4500 min -1, or in conditions where the intake manifold pressure below atmospheric pressure, the engine control unit supplies the control unit ignition signal that biases the ignition point toward earlier.
A WARNING The following test procedure applies only to models 1986 and 1987 model years, as when servicing cars later releases require special equipment, so you should apply to the service station. |
Check knock sensor Gently tap the probe of the voltmeter display ?�1U?� on the control box. At idle, the voltage shown by the voltmeter should be zero. If the reading is different, check the wire from the control unit to the control unit ignition timing (pin ?�G?�). Check ignition timing at idle, then remove the diagnostic socket on the control unit. Lightly tap with a hammer on the wall of the receiver and check whether the ignition timing is shifted towards later. If the ignition timing is shifted to a later, connect and then tap the wall of the receiver. Make sure that the ignition is not shifted to the later, which indicates normal operation of the ignition control. Otherwise, the control unit is faulty and should be replaced. If the first test the ignition timing is not shifted to a later, unplug the diagnostic connector, plug connector known-good knock sensor and connect it to the "weight". Lightly tap the sensor and check the displacement of the ignition timing to a later ignition. When the ignition is shifted to the later defective sensor. Otherwise, check the wiring from the sensor to the control unit. If the wires are OK, replace the ignition control. Replacement of components To replace the knock sensor disconnect the connector and remove the sensor from the engine block. Installation is performed in reverse order of removal. To replace the ignition control, disconnect the wire from the negative terminal of the battery. Disconnect from the power socket, remove the two screws and remove the block. Installation is performed in reverse order of removal.
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