It’s bad enough when your vehicle won’t start, but it’s even worse when it suddenly stops while you’re driving. This can be a frightening experience, but staying calm can help you act with a clear head. Using the momentum you have from driving, steer to the side of the road. Once you’re there, you can try to turn on your car, or simply get out and call for a tow truck.
Stalling like this isn’t very common. But when it does happen, there are a number of possible causes. We’ll go into detail on some of the more common ones below.
5. Trouble with Transmission
If you’re driving a car with a manual transmission, this may be an easy problem to fix. After all, braking too hard while the clutch is engaged can cause the car to stall, as can disengaging the clutch too quickly. If you’ve done this, simply restart your vehicle.
But if you’re driving a car with an automatic transmission, stalling can be a sign of a more serious problem. The torque converter is the automatic equivalent of a clutch; it’s a piece of machinery that connects and disconnects the transmission and the engine. If it fails to engage and disengage as it should, it may be what causes the engine to stop.
4. Faulty Mass Airflow Sensor
Your engine needs a steady supply of air in order to keep functioning. In modern fuel injected engines, a number of components are required to inject the precise mixture of fuel and air into the combustion chambers. The ECU, or engine control unit, gets information from a number of sensors and adjusts the injection based on this information. The mass airflow sensor, or MAF, is the sensor that’s responsible for telling the ECU the mass of the air that’s coming into the engine. If the MAF isn’t functioning as it should, the ECU may get incorrect information. If this happens, the ECU may direct less fuel to be injected, which can cause the engine to stall.
3. Fuel System Problems
If you’ve ever run out of gas, you know from experience just how quickly a lack of fuel can cause your car to stall. An empty gas tank is certainly one way that your engine might fail to get fuel, especially if you have a gas leak that’s making you lose fuel faster than expected. However, it’s not the only potential cause. The fuel pump helps move the gas from the fuel tank to the engine itself, so a fuel pump that fails while you’re driving can cause your car to stop. In addition, fuel injectors that are malfunctioning may keep enough fuel from reaching your engine.
2. Failed Alternator
The alternator plays several key roles in your vehicle’s functioning. It recharges the battery so that you can start your car when you need to, but it also runs the electric components of your vehicle. Among other things, it keeps the spark plugs sparking, which is a vital part of combustion. If the alternator begins to fail, the spark plugs may only sometimes function, causing rough and weak performance. An alternator that fails completely can cause the engine to stall, since the spark plugs won’t be creating any spark at all.
1. A Broken Timing Belt
While most Toyota models these days have a timing chain, many older vehicles were equipped with timing belts. These belts synchronize the strokes of the valves and pistons by making sure the camshaft or camshafts are synchronized to the rotation of the crankshaft. If the timing belt breaks in a freewheeling engine (that is, an engine where the pistons never occupy the same space as the valves), your engine will simply stop running. If your vehicle has an interference engine, your vehicle will also stop running . . . but the engine itself will likely be destroyed.