The fuel injector is located in the intake manifold, where it sprays fuel directly toward the intake valve of each cylinder, or mounted directly into the cylinder head for direct injection engines. In most modern port fuel injection systems, you'll find the injectors seated in the intake manifold, with their nozzles pointing into the intake ports. For gasoline direct injection (GDI) engines, the injectors are under much higher pressure and are threaded directly into the cylinder head, spraying fuel straight into the combustion chamber.
To find them, open the hood and look for the fuel rail, which is a long metal or plastic tube that runs along the top of the engine. The injectors are plugged into this rail. The electrical connector on top of each injector is a dead giveaway. The specific location can vary significantly depending on the engine layout.
| Engine Type | Typical Injector Location | Key Characteristic |
|---|
| Port Fuel Injection | Intake Manifold | Spray fuel into the intake port just before the intake valve. |
| Gasoline Direct Injection (GDI) | Cylinder Head | Spray fuel at high pressure directly into the combustion chamber. |
| Throttle Body Injection (TBI) | Throttle Body | A single or pair of injectors mounted above the throttle valve (older systems). |
| Diesel Engine | Cylinder Head | Extremely high-pressure injectors integral to the combustion process. |
Before attempting any work, you must relieve the fuel system pressure to avoid a dangerous spray of fuel. The safest method is to locate the fuel pump fuse in the vehicle's fuse box and start the engine, allowing it to stall from fuel starvation. Always disconnect the battery for safety. If you're not comfortable, this is a job best left to a professional mechanic.
