Replacing a fuel injector may sound like a complicated and involved task. However, with a bit of pre-planning and a few specialist tools, it’s very much a DIY job. Garages can charge hundreds of dollars to remove and inspect injectors, doing it yourself can save you serious money!
You are about to disconnect multiple fuel lines and potentially spill highly flammable fuel. It is important then to be very careful. Make sure your engine is cold and you disconnect the battery to prevent any chance of spilled fuel igniting.
Wear eye protection in case you splash gas near your eyes and have some clean rags to hand to mop up any spills. Wear gloves to guard against fuel damaging your skin.
- Eye protection.
- Wrenches of assorted sizes.
- Sockets of assorted size.
- Injector Remover / Slide hammer.
- Some cars may use torx fixings and splined fittings (called triple square sometimes).
Remove Fuel Injector Instructions
Step One: Locate your injectors
The first step is to locate your injectors. On modern cars, they may be hidden away under various pieces of engine bay plastic trim pieces, so you might have to remove those and place them to one side carefully. You are looking for electrical plugs that are connected to cylindrical components that are sticking out of the cylinder block. Follow the fuel lines from your fuel pump if you are stuck, the injectors will be on the other end of them.
One some vehicles, injectors are fitted vertically and are easy to access, on others they can be at more of an angle and obscured by numerous other ancillary components. On others, your injectors may be fitted under the rocker cover, take a look at your manufacturer’s workshop manual for guidance.
Step Two: Safety steps
Make sure you’ve disconnected the battery, have some cloths on hand and the engine is cool
Step Three: Relieve Fuel System Pressure
Refer to the manufacturer’s instructions on how to relieve pressure from the system. This prevents fuel from blasting all over the place as you remove the fuel rails.
Step Four: Remove Fuel Lines / Rail
You need to remove the fuel manifold or rail that supplies fuel to the injectors; this is often held on with only a few fixings. If there’s a wiring loom fixed to it, disconnect it. Have your cloth on hand to catch any fuel spills.
On some engines, each injector has a steel feed pipe; these have a large union on one end that attaches it to the injector. You have to remove these; sometimes it is necessary to use a crows foot type wrench.
Step Five: Disconnect Electrical Connectors
On top of the injector, there will be a multi-plug or several wires. These need to be removed. Be careful not to damage them. Some of the multi-plug electrical connectors will have safety pins that also have to be removed. Once unplugged, place these safely to one side.
Step Six: Remove the injectors
The injectors may have become stuck fast due to the effects that heat has on them. Corrosion can also set in and cause them to be stubborn to remove. Carefully attach your sliding hammer/injector remover and firmly move the slider to begin loosening the injector. This may take some time and patience. Only pull in-line with the injector body, not off at an angle that could damage the injector. Be ready for when it suddenly comes free.
Make sure that when the injector is removed, no debris can fall into the hole it leaves. Also ensure to put your injectors somewhere clean, away from dust and trash.
No Injector Puller?
What if you are stuck in the bush or have broken down at the road side and need to service an injector? And you’ve left your fancy injector puller at home!
It is possible in some cases to use wood to remove the injector. Also, on some injector housings, they have 2 flats for a wrench, so that you can wiggle them free.Read more: Top Pneumatic Impact Wrench 
To remove using wood, you’ll need a few blocks of wood to place on something solid, such as the suspension top hats or inner arches. You’ll also need a long piece of wood to bridge between the two blocks and run over the top of your injector.
Then, tie some sturdy rope around the injector, preferably at its strongest point. Tie a loop in the other end and feed the long piece of wood through it. You can then lift this plank and use it as a lever to pull out the injector. If you are struggling, try a longer piece of wood for more leverage.
To refit, follow the removal instructions in reverse.