Gloves can protect your hands from sharp objects or pinches while working in the engine bay. Eye protection is required for this project.
The fuel rail is a cylindrical rail that will run along the top of the intake manifold, and each fuel injector will be between the fuel rail and the intake manifold. V style engines (V6, V8, V10) will have two fuel rails with half of the injectors on each side of the motor.
Make sure the piece you choose is at least a foot long, but not more than two feet. A long screwdriver or thin piece of rebar will work fine.
Make sure to hold the screwdriver or metal rod at an angle that will allow you to bring your ear to it.
Be extremely careful leaning your head into the engine bay, and ensure you keep your eyes open as you listen to the rod to prevent accidentally getting injured. If you have long hair, tie it back tightly to prevent it from getting caught in any moving parts under the hood.
If you have an OBDII scanner and your vehicle’s check engine light is on, you can check to see if there have been any errors in the vehicle’s computer regarding that cylinder or injector. Replacing this injector may solve the problem, but you may also need to have a diagnostic done of your vehicle’s electronic control unit and fuel system by a professional mechanic. [8] X Expert Source Duston MaynesAutomotive Repair Specialist Expert Interview. 11 June 2021.
If you accidentally start the vehicle, simply turn it off and try again. The vehicle’s battery is powering everything during this test, so you should turn off things like the headlights and stereo to conserve power and ensure it has enough to start the vehicle again later.
You can identify the negative terminal on the battery by looking for the negative symbol (-) or the letters NEG. Make sure the clip has a good metal on metal connection to make the test light work.
These wires are often grey and black, but can come in any number of colors. They will be the only wires coming from each injector.
Make sure to wrap a piece of electric tape around any holes in the wiring’s protective coating that are big enough to see. If neither wire makes the light turn on, then there is an issue with the power reaching the fuel injector, which will result in in failing to fire. If the all of the wires that light up are a certain color, make note of which wires are the constants.
Follow the wires on the injectors that fail to engage the test light to make sure there are no breaks in the wire that may prevent the electricity from reaching it. Let your mechanic know that you were able to identify the injector with a power issue. It may require replacing the vehicle’s electronic control unit.
You can identify the positive terminal by looking for the positive sign (+) on the battery or the letters POS. Make sure the alligator clip has secure, metal on metal contact or the test light will fail to function.
If the engine won’t start, remember that attempting to turn it over for too long can kill the battery and damage the starter. Only attempt to turn it over with the test light in place.
Be careful not to press the probe all the way through the wire and out the other side. Always cover holes in the wire’s protective coating with electric tape once you’re done.
This issue could be caused by a failing ECU, or one of the injectors along the fuel rail may be faulty. The electrical pulse is transmitted through each of the injectors to one another, so one faulty injector could cause issues in multiple injectors.
When the pulsing light dims as you connect one of the injectors, that injector is faulty and needs to be replaced. You can purchase new fuel injectors for your vehicle at most auto parts stores.
