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.
Air Induction
Air is drawn into the combustion chamber through the air cleaner and intake manifold. The amount of air entering the engine is controlled by the position of the throttle body valve. The throttle body houses the TPS and ISS motor. The TPS is an electrical resistor which is connected to the throttle valve. The TPS transmits a signal to the ECU in relation to throttle valve angle. From this signal, the ECU calculates fuel injector "on" time to provide adequate air/fuel mixture.
The ECU controls the idle speed by providing the appropriate voltage outputs to move the ISS motor pin inward or outward to maintain a predetermined idle speed. The ECU continuously monitors the TPS and ISS motor and issues change commands to the injectors to increase or decrease the amount of fuel injected.
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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.