Replacing Fuel Injectors In Your 1995 Mazda 626: Step-By-Step Guide

If you're experiencing problems with your 1995 Mazda 626, a faulty fuel injector could be to blame. In this article, we'll cover the steps to replace the fuel injectors in your vehicle, as well as some tips for testing and identifying a faulty injector. It's important to note that fuel injector replacement can be complicated, so unless you have a good grasp of the process and the necessary tools, it's best to leave it to a professional mechanic. With that said, let's begin!

Test each injector with an ohm meter

To test each fuel injector with an ohm meter, you will first need to locate the fuel injectors. There should be one per cylinder, typically a black plastic housing installed directly above the cylinder. Next, follow these steps for each injector:

• With the vehicle turned off, disconnect the electrical connector for the fuel injector.
• Put the digital multimeter to the right value on the Ohms scale according to the resistance specs for your fuel injector. Most fuel injectors should read between 10 and 18 ohms, but you can check your vehicle's service manual or look online to learn the correct value.
• Check the injector electrical terminals. Polarity does not matter.
• A resistance reading other than the specified in your service manual means you need to replace the injector. For example, if your reading is jumping, the coil is likely partially open. If your meter reads infinite resistance, the coil is probably open, and if you read zero resistance, the coil is likely shorted.

It is important to test each injector to ensure they are all functioning properly. A faulty injector can cause your engine to run poorly or even stop running altogether.

Release the pressure from the system

Releasing the pressure from the system is an important first step when changing fuel injectors. This is done by removing the green relay in the fuse box.

First, make sure the engine is cold to the touch and disconnect the battery. Next, remove any plugs connected to a wiring harness. You can then use pliers to disconnect the electrical connector on each injector.

It is important to relieve the fuel system pressure before proceeding with fuel injector replacement. This is done by disconnecting the fuel line (hose) and the fuel rail.

Disconnect the vacuum hoses

Disconnecting the vacuum hoses is a crucial step in changing out fuel injectors for a 1995 Mazda 626. Here is a detailed guide on how to do this:

Locate the vacuum hoses: Vacuum hoses are usually found near the fuel injectors and fuel regulator. They are typically made of rubber or plastic and are connected to various components of the engine.

Gather the necessary tools: Before starting, ensure you have the right tools for the job. You will likely need a set of wrenches, pliers, and possibly a screwdriver. It is also recommended to have a rag or towel handy to wipe up any fuel spills.

Relieve the fuel system pressure: Before disconnecting any hoses, it is important to relieve the pressure in the fuel system. This can be done by removing the green relay in the fuse box.

Start disconnecting the vacuum hoses: Begin by carefully releasing the clamps or couplers that secure the vacuum hoses in place. Some hoses may be held in place with hose clamps, while others may have quick-release couplers. Gently pull the hoses away from the fuel injectors and fuel regulator.

Identify the hoses: As you disconnect each hose, take note of its location and orientation. It is important to know where each hose connects so that you can properly reconnect them later. You may want to take pictures or make notes for reference during reassembly.

Remove the hoses: Once all the clamps or couplers have been released, carefully pull the hoses away from the fuel injectors and fuel regulator. Be gentle to avoid damaging the hoses or the components they are connected to.

Inspect the hoses: With the hoses disconnected, take a moment to inspect them for any signs of damage, cracks, or leaks. If any hoses appear damaged, it is recommended to replace them with new ones.

Clean the connection points: Before reconnecting the hoses, use a clean rag to wipe down the connection points on the fuel injectors and fuel regulator. This will help ensure that there is no dirt or debris that could cause leaks or impede performance.

At this stage, with the vacuum hoses disconnected, you can continue with the next steps of changing out the fuel injectors. Remember to refer to your repair manual or seek guidance from a professional mechanic if you are unsure about any part of the process.

Disconnect the plugs to the injectors

Disconnecting the plugs to the injectors is a crucial step in changing out fuel injectors in a 1995 Mazda 626. Here is a detailed guide on how to do this:

First, ensure that you have released the pressure from the system by removing the green relay in the fuse box. This is an important safety measure as it helps to reduce the risk of fuel leakage and other potential hazards. Next, locate the plugs connected to the injectors. These plugs are part of the wiring harness, which supplies power to the injectors. Using a pair of pliers, carefully disconnect the electrical connector on each injector. It is important to be gentle during this step to avoid damaging the connectors or the harness.

For the next step, you will need to gain access to the fuel injectors themselves. To do this, carefully lift the fuel rail off the intake manifold. This will expose the fuel injectors and provide the necessary space to work on them. Be cautious when handling the fuel rail, as it contains fuel and is connected to sensitive components. Once the fuel rail is lifted, you will have access to the fuel injectors and their connectors.

Now, you can begin disconnecting the plugs from the injectors. Gently pull each plug away from its injector, one at a time. It may be necessary to wiggle the plug gently back and forth to loosen it before pulling it away. Ensure that you pull directly on the plug itself and not on the wires, to avoid any damage to the wiring. Take care to avoid pulling or straining the wires during this step. Place the disconnected plugs somewhere safe and out of the way to prevent accidental reconnection or damage.

At this point, the plugs to the injectors should be successfully disconnected. It is important to note that working on fuel injectors can be dangerous due to the presence of flammable fuel and pressurized components. If you are uncomfortable or unfamiliar with any of these procedures, it is recommended to seek the assistance of a qualified mechanic.

Remove the fuel rail

To remove the fuel rail of a 1995 Mazda 626, follow these steps:

Firstly, relieve the fuel system pressure. To do this, remove the green relay in the fuse box.

Next, disconnect the vacuum hoses. Disconnect the vacuum from the fuel regulator, and then disconnect the plugs to the injectors.

Now, disconnect the gas line from the fuel regulator. Place a rag under the main fuel line to avoid dropping the washer from the connector.

Remove the bolt, and then the fuel hose between the fuel rails.

Now, carefully slide the rail out, being careful not to drop the plastic washers/spacers for the two bolts.

Remove the rail from the front in the same way, by removing the bolts and carefully sliding out the rail.

Once the rail is off, remove the screws on the rail.

Frequently asked questions