Why does my car idle, but then die when I hit the throttle?

Faulty Idle Air Control (IAC) Valve

The Idle Air Control valve regulates the amount of air entering the engine at idle. If it’s malfunctioning, your car may idle smoothly but struggle when you increase the throttle, leading to stalling. A dirty or faulty IAC valve might be the culprit.

Clogged Fuel Filter

A clogged fuel filter restricts the flow of fuel to the engine. While the car may get enough fuel to idle, the moment you hit the throttle, the demand for fuel increases, causing the engine to die because it isn’t receiving the fuel it needs.

Bad Throttle Position Sensor (TPS)

The Throttle Position Sensor monitors the position of the throttle and sends information to the car’s computer to adjust the air-fuel mixture accordingly. If the TPS is faulty, it might not be sending the correct signals, leading to improper fuel delivery when you press the throttle.

Dirty or Faulty Mass Air Flow (MAF) Sensor

The Mass Air Flow sensor measures the amount of air entering the engine and helps determine the correct amount of fuel to inject. If the MAF sensor is dirty or faulty, it can send inaccurate data, causing the engine to stall when you attempt to accelerate.

Vacuum Leaks

A vacuum leak can cause the engine to receive more air than it should, leading to a lean air-fuel mixture. This imbalance can cause the engine to stall when you hit the throttle, as the engine struggles to compensate for the extra air.

Failing Fuel Pump

The fuel pump is responsible for delivering fuel from the tank to the engine. If the pump is failing, it might not be able to maintain the required pressure when you press the throttle, causing the engine to stall due to a lack of fuel.

Ignition System Issues

Problems with the ignition system, such as faulty spark plugs, ignition coils, or wires, can prevent the engine from firing properly under load. While the car may idle smoothly, it may stall when you demand more power by pressing the throttle.

Blocked or Dirty Fuel Injectors

Fuel injectors are responsible for spraying fuel into the engine’s combustion chamber. If they’re blocked or dirty, the engine might not receive enough fuel when you press the throttle, leading to stalling.

Malfunctioning Engine Control Unit (ECU)

The Engine Control Unit is the brain of your car, managing all engine functions. A malfunctioning ECU can cause erratic engine behavior, including stalling when the throttle is applied.

Check Engine Light On?

If your car’s check engine light is on, it’s a clear indication that something is wrong. A diagnostic scan can help identify the specific issue, making it easier to address the problem.

Conclusion

If your car idles fine but dies when you hit the throttle, it's important to have it checked by a professional. Ignoring the problem can lead to more severe damage over time.

For reliable and professional assistance, contact MyMechanic Malaysia. They offer expert services to resolve any throttle-related issues efficiently, ensuring your car runs smoothly. Don’t wait—reach out to them today to keep your car in top condition!