System Description
All 1984-91 vehicles are equipped with an electronic ignition system. There are no contacts and no capacitor in this system; it does not require periodic maintenance.
The electronic ignition systems used on the 198489 Accord and the carbureted Prelude 1984-90 use a distributor with magnetic pulse-switching ignition and conventional (standard) ignition coil. Distributor cap, rotor, ignition timing (vacuum and centrifugal) and the secondary ignition winding are also standard. The distributor contains a stator, magnetic resistance and a pulse generator (master coil) and breaker assembly. During operation, the teeth of the magnetic resistance are aligned with the stator, the pulse generator produces 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 ignition wires to the spark plugs.
On systems used in Accord (1990-91) and Prelude (1989-91), both fuel-injected, the distributor components send signals to the engine computer. ECU (computer) switches the candles through the breaker block 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 sensor (TDC) first cylinder. Using these and other electrical sensors, the computer controls the ignition timing electrically. This system eliminates the need for mechanical and/or vacuum ignition 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. Observe 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 markings on the battery and the conformity of the cables before connecting, especially if the battery has been removed and may have been reinstalled in the opposite position. Incorrect polarity will cause current flow through the electronic ignition system in the opposite direction and immediately ruin the system.
3. Do not allow wires connected to the pulse generator to touch other wires of the ignition system.
4. Wrong (abnormal) voltage surges can damage the system. Be sure to either disconnect the battery or turn off the ignition system before doing any electrical work on the vehicle.
5. It is allowed to connect any electric tachometer only with negative (-) output of the ignition coil and no other connection.
6. Always double check any connection to the ignition system before connecting the battery and putting the system into operation.
7. When starting the engine for compression testing or similar purposes, disconnect the coil wires in the distributor.