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 combustion chamber through air cleaner and intake manifold. Amount of air entering engine is controlled by position of throttle body valve. Throttle body houses throttle position sensor (TPS) and idle speed solenoid (ISS) motor. TPS is an electrical resistor which is connected to throttle valve. TPS transmits a signal to ECU in relation to throttle valve angle. This signal is used in calculations to determine injector pulse width to provide adequate air/fuel mixture.
ECU controls idle speed by providing appropriate voltage outputs to move ISS motor pin inward or outward to maintain a predetermined idle speed. ECU continuously monitors TPS and ISS motor and issues change commands to injectors to increase or decrease amount of fuel injected.
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.