Ignition system — general information (Nissan Patrol Y60)

The Patrol/Maverick vehicles covered by this manual are equipped with one of two types of ignition systems. The 4.2L models are equipped with a conventional distributor ignition system with a contact breaker, while the 3.0L models use an electronic distributor. Both distributors are driven by a helical gear from the camshaft and are equipped with vacuum and centrifugal ignition timing correctors. The 3.0L models are additionally equipped with a thermal vacuum valve (TVV) to control the operation of the vacuum corrector. The valve prevents the supply of vacuum to the distributor corrector until the engine has warmed up to a specified temperature.

In the distributor of 4.2L models, a mechanical contact breaker is used to interrupt the power supply to the primary circuit of the ignition coil. In the electronic distributor, a control pulse sensor is used instead of the breaker contacts, and the primary current of the ignition coil is controlled by a switch. When the power supply is interrupted, high voltage is induced in the secondary winding of the coil, which is supplied to the spark plugs through the high-voltage wires through the distributor rotor. On 4.2L models, a ballast resistor is used to further increase the ignition voltage during engine starting.

Both types of distributors are equipped with an engine speed limiter consisting of a runner and a special screen located under the runner. The runner is equipped with a spring-loaded sliding electrode and a switching electrode. When the engine speed reaches 5000÷5400 rpm, the centrifugal force pushes the sliding electrode outward, bringing it into contact with the switching electrode. The ignition current of cylinders 1, 3, 4 and 6 is then directed through the switching electrode and the screen plate to the high-voltage terminals of cylinders 2 and 5, which leads to a decrease in engine speed.

(Read more on the website www.nissanbook.ru)