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.
Fuel Injection System - TBI: Description
Chrysler Corp. throttle body fuel injection system is controlled by pre-programmed digital computer (logic module). Logic module controls ignition timing, emission control devices, idle speed and air/fuel ratio. Logic module converts input signals from sensors and switches into control signals.
Input sensors used by logic module are Manifold Absolute Pressure (MAP) Sensor, Throttle Position (TPS) Sensor, oxygen sensor, coolant temperature sensor, throttle body temperature sensor and vehicle distance sensor. Switches used include idle switch, neutral safety switch, A/C clutch switch and brake light switch.
Control (output) signals from logic module are sent to power module. Power module then sends electrical signal to appropriate component in order to alter mixture and/or ignition timing. Amount of fuel metered through injector is controlling factor in air/fuel ratio.
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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.