The spark test is used to see if the ignition system is delivering electricity through the coil wire to the distributor. Use this test as a preliminary test if the engine cranks but won't start. It's a simple test, but can give a nasty shock if NOT performed correctly.
Spark plug cables should be treated carefully and always routed in the factory locations and secured with the factory clips. The high voltages these systems can produce can cause improperly routed cables to induce crossfire voltages into other cables, resulting in misfire and possible engine damage. Makes sure the spark plug cables are in good condition and properly positioned.
Spark plug cables can be removed and tested with an ohmmeter. All systems using spark plug cables carry a specification of 25 k-ohms per cable.1FZ-FE and 2RZ-FE Engines
- Disconnect the end of the coil wire at the distributor.
- Use a well-insulated tool (such as ignition wire pliers) to hold the exposed end of the wire about 1 / 2 inch (13mm) from the metal of the engine block.
- Have an assistant crank the engine by turning the ignition switch to the START position, but only for one or two seconds. Keep clear of moving parts under the hood, and keep clothing and hair well out of the way. If the cable end is the correct distance from solid metal, and if the ignition system is in good condition, a distinct, blue-white spark should jump to the metal as the engine cranks.
- The engine should only be cranked in 12 seconds bursts. Longer cranking will cause the fuel injectors to deliver additional fuel into the cylinders, flooding the engine or at least fouling the spark plugs.
- If no spark is present, turn the ignition switch OFF and proceed to check the resistance of the of the coil wire, the voltage supply to the coil (12 volts with the ignition ON ), the coil resistance, the resistance of the pickup coil and the air gap within the distributor.