Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine Electrical: Design: Injectors
The function of the injectors is to spray fuel into the cylinders in the correct spray patterns. This happens sequentially.
The injectors are in the intake manifold.
It is essential that the injectors are correctly installed with no air leakage around them. Fuel leakage from the top of an injector when it is not activated may lead to starting and driving problems.
The engine control module (ECM) controls the injectors using a pulse width modulation (PWM) signal.
The engine control module (ECM) can diagnose the injectors. The injectors can be activated using VIDA.
Air-shrouded injectors
Cars from model year 1999-2000 have air-shrouded injectors.
The injectors are in the air distribution pipe which is in the intake manifold.
The lower section of the injectors has 2 openings in the side where air can enter.
When the needle in the injector starts to rise, the openings are exposed. This allows air to flow in to the center of the valve at high speed, and the fuel and air are finely distributed and mixed.
When the needle rises further, the injector nozzle opens and the air/fuel mixture is released into the combustion chamber.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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