Description of the system
All cars produced between 1984 and 1991 are equipped with an electronic ignition system. This system does not have contacts or a capacitor; it does not require periodic maintenance.
The electronic ignition systems used in the 1984-89 Accord and the carbureted 1984-90 Prelude use a magnetic pulse-interrupter distributor and a conventional (standard) ignition coil. The distributor cap, rotor, ignition timing mechanism (vacuum and centrifugal), and secondary ignition winding are also standard. The distributor contains a stator, magnetic reluctance, a pulse generator (setting turn), and an interrupter assembly. During operation, the teeth of the magnetic reluctance align with the stator, the pulse generator generates a signal sent to the interrupter module. In the module, when a signal is received, the primary winding of the ignition coil is connected. The primary magnetic field causes a high voltage to appear in the secondary winding. This high voltage is transmitted from the coil to the distributor cap and rotor, and through the secondary spark plug wires to the spark plugs.
In the systems used in the Accord (1990-91) and Prelude (1989-91), both fuel injected, the distributor components send signals to the engine computer. The ECU (computer) switches the spark plugs via a breaker assembly and coil. The spark timing is controlled by the computer as one of the built-in functions of the fuel delivery system. The distributor contains a crankshaft angle sensor and a top dead center (TDC) sensor for cylinder number one. Using these and other electrical sensors, the computer controls spark timing electrically. This system eliminates the need for mechanical and/or vacuum advance devices in the distributor.
Diagnostics and testing
Your Honda's electronic ignition system requires special handling. Unlike a conventional ignition system, this system is very sensitive to sudden voltage changes or reverse polarity. Follow the precautions listed below to avoid damaging your expensive system.
1. Be sure to disconnect the battery cables before repairing the electronic ignition system.
2. Always double check the battery markings and cables before connecting, especially if the battery has been removed and may have been reinstalled in the opposite direction. Incorrect polarity will cause current to flow through the electronic ignition system in the opposite direction and will immediately ruin the system.
3. Do not allow wires connected to the pulse generator to touch other wires of the ignition system.
4. Incorrect (abnormal) voltage pulses can damage the system. Make sure that either the battery is disconnected or the ignition system is turned off before performing any electrical work on the vehicle.
5. Any electrical tachometer may only be connected to the negative (-) terminal of the ignition coil and no other connection.
6. Always double check any connection related to the ignition system before connecting the battery and starting the system.
7. When starting the engine for compression testing or similar purposes, disconnect the coil wires at the distributor.