A distributor is an important component in older ignition systems used in gasoline engines. It distributes high-voltage electric current from the ignition coil to the spark plugs, which ignite the fuel in the engine's combustion chamber.

To know if a distributor needs to be replaced depends on if it's a conventional type distributor or electronic type distributor. In general, if the distributor cap or rotor is cracked, corroded or worn out, it can cause the engine to misfire or stall. If there is excessive play in the distributor shaft or if the bearings inside are worn, a replacement may be necessary. Additionally, if the pickup coil inside the distributor is failing, it can cause stalling, lack of power or a no-start condition.