Datsun/Nissan pick-ups sold in California beginning in 1976 are equipped with electronic ignition. All 1978 and later trucks are also equipped with the system. The 1978 system differs somewhat from the earlier system and the 1979 and later system is markedly different.
The electronic ignition differs from its conventional counterpart only in the distributor component area. The secondary side of the ignition system is the same as a conventional breaker points system.
Located in the distributor, in addition to the normal ignition rotor, is a four spoke rotor (reluctor) which rests on the distributor shaft where the breaker points cam is found on earlier systems. A pick-up coil, consisting of a magnet, coil, and wiring, rests on the breaker plate next to the reluctor. The system also uses a transistor ignition unit, located on the right side of the firewall in the passenger compartment, through 1978. All 1979-80 models have an integrated circuit (IC) ignition unit, which is mounted on the side of the distributor. In addition, 1979-80 models use a ring-type pick-up coil, which surrounds the reluctor, rather than the arm-type coil used through 1978.
When a reluctor spoke is not aligned with the pick-up coil, it generates large lines of flux between itself, the magnet, and the pick-up coil. This large flux variation results in high generated voltage in the pick-up coil, preventing current from flowing to the pick-up coil. When a reluctor spoke lines up with the pick-up coil, the flux variation is low, thus, zero voltage is generated, allowing current to flow to the pick-up coil. Ignition primary current is then cut off by the electronic unit, allowing the field in the ignition coil to collapse, inducing high secondary voltage in the conventional manner. The high voltage then flows through the distributor to the spark plug, as usual.
Because no points or condenser are used, and because dwell is determined by the electronic unit, no adjustments are necessary. Ignition timing is checked in the usual way, but unless the distributor is disturbed it is not likely to ever change very much.
All 1981 and later models are equipped with a different ignition system and do not utilize a pick-up coil. This system uses two ignition coils and each cylinder has two spark plugs which fire simultaneously. In this manner the engine is able to consume large quantities of recirculated exhaust gas which would cause a single spark plug cylinder to misfire and idle roughly.