1. Vacuum Leak:
* What it is: A hole or crack in the vacuum lines that connect to the brake booster.
* How it affects the engine: The brake booster relies on engine vacuum to assist in braking. A leak weakens the vacuum, causing the engine to stall when braking.
* Symptoms: Engine cuts off, especially during heavy braking, rough idling, or the engine dying while stopped at a light.
2. Brake Booster Failure:
* What it is: The brake booster is a vacuum-powered device that assists in braking. It can fail due to age, wear, or internal leaks.
* How it affects the engine: A faulty booster won't provide sufficient assistance to the brakes, potentially causing the engine to stall when braking.
* Symptoms: Difficult to brake, especially at low speeds, a spongy brake pedal, and a hissing sound when applying the brakes.
3. Engine Idle Issues:
* What it is: Problems with the idle control system (ICS) can cause the engine to stall when the load from braking is applied.
* How it affects the engine: The ICS regulates engine speed at idle. A malfunction can lead to low idle RPM, making the engine susceptible to stalling under load.
* Symptoms: Rough idle, stalling at traffic lights, and the engine dying when the air conditioner is turned on.
4. Defective Throttle Position Sensor (TPS):
* What it is: The TPS sends a signal to the engine control unit (ECU) about the throttle position. A faulty TPS can provide incorrect information, causing the ECU to misinterpret the engine's state.
* How it affects the engine: If the TPS fails, the ECU might shut off fuel supply, leading to engine stalling, especially when braking.
* Symptoms: Engine stalling during acceleration or deceleration, poor fuel economy, check engine light.
5. Electrical Issues:
* What it is: A faulty wiring connection, corroded terminals, or a short circuit in the ignition system can interrupt the flow of electricity to the engine.
* How it affects the engine: Interruption in the electrical system can cause the engine to stop running.
* Symptoms: Engine cutting out intermittently, flickering lights, or other electrical malfunctions.
6. Fuel System Issues:
* What it is: A clogged fuel filter, fuel pump failure, or issues with fuel injectors can prevent fuel from reaching the engine.
* How it affects the engine: Lack of fuel can cause the engine to stall, especially under load.
* Symptoms: Engine sputtering, hesitation, rough idle, and the engine dying while driving.
Important Note: If your engine cuts off when you brake, it's crucial to get your car checked by a qualified mechanic as soon as possible. This issue can be dangerous and could lead to an accident.
