Fuel Injector Test
Test Fuel Injector - When a fuel injector malfunctions it can allow excessive or a minimal amount of fuel into the engine. The fuel injector is manufactured with a pintle valve that allows fuel to flow at prescribed amounts. If this valve sticks open it can flood the cylinder with fuel. If the valve sticks closed no fuel is allowed into the engine cylinder. Both excess and the absence of fuel can cause black smoke from the exhaust pipe. When an injector is stuck closed the absence of fuel will cause the cylinder to run lean, effectively fooling the oxygen sensor and causing the system to add too much fuel into the engine through the remaining fuel injectors. (A common misconception about a cylinder misfire causes the engine to run rich, in reality the cylinder runs lean which causes the aforementioned lean condition.) Performing a few basic tests you can determine if one or more fuel injectors have failed causing an engine run-ability problem. Difficulty Scale: 3 of 10 This test pertains to all cars that utilize an electronic fuel injector system. Tools and Supplies Needed
- Test light or voltmeter
- Small standard screw driver
- Wrench set
- Socket set
- Protective eyewear and gloves
- Shop towels
- A fuel injector is subject to high temperatures that can cause the injector to short circuit. Each injector has specific ohms of resistance reading that can be tested. This ohms reading can be found in a car repair manual. Temperature will cause readings to vary slightly. Injectors should be tested hot and cold. This is necessary because the heat or cold can create a condition that can short circuit the injector.
- Moisture can cause the injector connection to short circuit. Always inspect and clean all electrical connections at the fuel injector.
- When replacing fuel injectors always use top quality replacement parts.
- Fuel is present when working with injectors so use caution.