Ignition distributor cap: replacement and selection

When and why it is necessary to replace ignition distributor cap

The ignition distributor cap has no lifetime limit specified by manufacturers and is replaced in case of rupture, mechanical damage, and in case of strong corrosive damage of contacts.

Rupture of the component is caused by an increase in the gaps between its contacts and the rotor, which is a consequence of the gradual destruction of metal under the influence of electrical discharges. Moreover, this defect can be the result of usage of poor-quality spark plugs and tips of high-voltage wires. Oxidation of the cap contacts, usually, occurs due to operation of the car in conditions of excessive air moisture.

Unstable operation of the engine at idling, jerks of the car during driving and inability to start the engine point out defects of the ignition distributor cap. In rainy weather, the engine may not gain rotation speed if the ignition distributor cap operates improperly.

Assess condition of the rotor during replacement of the part. If it is worn-out or cracks are visible on it, replace it together with the cap.

How to select ignition distributor cap

The ignition distributor caps are made of various materials. The most common are the components made of heat-resistant polyester and polyethylene. The parts of the first type are notable for durability and resistance to temperature changes. This increases their reliability, but at the same time troubles visual inspection. If the part is made of less durable polyethylene, its rupture or mechanical damage is quite visible during inspection.

Moreover, the ignition distributor caps vary by fastening type: they can be fixed with bolts or latches. Bolts fasten the cap securely, but its demounting and installation take more time in comparison with the latch-fastened component. Also the caps vary by contacts quantity. It depends on quantity of the spark plugs and presence or absence of central high-voltage wire.

High-quality and durable components, providing stable engine operation are produced under such brands as Bosch, Facet, Stark, JP Group, Topran, Ashika and others.

When choosing the ignition distributor caps, define how many wires should be connected to the required component: the caps vary by electrodes quantity. If the part is fastened by bolts, also specify their quantity.