The ignition system uses a unit consisting of two separate two-terminal ignition coils. Current in the primary windings of the ignition coils is controlled by a controller that receives information from sensors and uses two powerful transistor valves.
The ignition system has no moving parts, so it is maintenance-free and does not require adjustments.
The ignition system uses a spark distribution method called the idle spark method. The engine cylinders are paired 1-4 and 2-3, spark formation occurs simultaneously in two cylinders: in the cylinder in which the compression stroke ends (working spark), and in the cylinder in which the exhaust stroke occurs (idle spark).
Due to the constant direction of current in the windings of the ignition coils, the spark current for one spark plug always flows from the central electrode to the side electrode, and for the second one - from the side electrode to the central one,
The ignition system is controlled by a controller. The crankshaft position sensor supplies the controller with a "reference" signal, based on which the controller calculates the firing sequence of the coils in the ignition module. For precise ignition control, the controller uses the following information:
- crankshaft speed;
- engine load;
- coolant temperature;
- crankshaft position;
- camshaft position;
- presence of detonation.
To check the ignition coils, follow these steps:.
1. Disconnect the wire from the negative terminal of the battery.
2. Remove the decorative engine cover (see "Removal and installation the decorative engine cover").
3. Disconnect the high-voltage wire tips and wiring harness connectors from the ignition coils (see "Removal and installation ignition coils").
4. Measure the resistance of the secondary windings of the ignition coils by connecting the tester leads to the first and fourth, and then to the second and third high-voltage terminals. The resistance of the secondary windings at a temperature of 21-27°C should be about 11.5-13.5 kOhm.
Note: For clarity, the test is shown on coils removed from the vehicle.
5. If the secondary winding resistance is significantly different from the specified value, replace the ignition coil assembly.
6. Measure the resistance of the ignition coil primary windings by connecting the tester leads to the terminals of the coil primary windings. The resistance of the primary windings at a temperature of 21-27°C should be about 1-2 ohms.
7. If the primary winding resistance is significantly different from the specified value, replace the ignition coil assembly.
(The article was borrowed from the website ChevyMan)