Why Does My Car Start Then Turn Off? (11 Reasons Why)

Does your vehicle start right up and then end up dying? Maybe it won’t start unless you step on the gas?  There are a few simple steps you can take to resolve the problem.

Unfortunately, diagnosis of a no-start or unexpected stall condition is difficult because of numerous possible causes. But, you don’t have to worry; this post will assist you in narrowing down the issue. So, let’s find out more!

Why Does My Car Start Then Turn Off?

There are numerous reasons why your car would start and then immediately stop, including things like a bad idle air control valve, vacuum leakage, or a faulty or dirty MAF sensor. Also, the problem could be attributed to an ignition system issue, poor camshaft-crankshaft position sensor, fuel pump leak, fuel injection sensor problem, or a faulty carburetor.

If you are still interested in knowing more about why your car starts and suddenly turn offs, then here are 11 reasons; read more!

1. Faulty Idle Air Control Valve

At idle, an idle air control valve controls the fuel-air mixture of your vehicle.

Also, it maintains the idle under shifting engine loads, such as when you turn on the air conditioning, headlights, or radio.

If the valve fails, you may encounter a rough idle, or worse, and your vehicle may completely stall.

2. Vacuum Leakage

A vacuum leakage is a hole in the air intake system of a vehicle located behind the mass air flow (MAF) sensor that enables unmetered air into your engine.

Further, it deviates from the expected air-fuel ratio, causing the car to run lean.

Conversely, an overly lean air-fuel mixture may end up causing your vehicle to rattle when starting and die quickly.

3. Faulty Or Dirty MAF Sensor

With most vehicles, a mass airflow (MAF) sensor measures the amount of air accessing the engine.

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Grime and oil buildup from the engine air filter could quickly clog the sensor. Also, a dirty sensor will frequently read incorrect air measurements, causing the air-fuel ratio to be off.

With that, flushing this sensor with a MAF sensor cleaning solution may resolve the problem. If not, check the MAF sensor for damage and consider replacing it if necessary.

If you’re using an aftermarket air intake, don’t over-oil the air filter because too much oil may pass through the filter and clog the MAF sensor.

4. Ignition System Issue

The ignition system takes care of producing the spark that ignites the air-fuel mixture in the internal combustion chamber.

So, whenever you have problems with your ignition system, the spark may not be vital enough to complete combustion in your vehicle’s combustion chamber.

If the car is running at all, this might end up causing it to die. So first, check the battery has a solid connection with no rust on the terminals.

Additionally once the terminals are heavily corroded, try cleaning them. A battery terminal cleaner is designed specifically for this use and simplifies the job.

5. Poor Camshaft/Crankshaft Position Sensor

Camshaft and crankshaft position sensors are intended to constantly inform the ECU of the location of the crankshaft or camshafts.

With that, it enables the ECU to arrange the ignition of the spark plugs with the rotating assembly’s position.

So, when the ECU does not receive a clear message, the engine may struggle to start or die soon after.

6. Slipped Timing Belt

Slipped Timing Belt

A toothed timing belt or chain will throw off the cam timing, causing the intake and exhaust valves to open at the incorrect time.

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That said, inaccurate cam timing can cause a rough idle, misfiring, and engine stalling.

Further, a skipped tooth could’ve been caused by a loose belt, which could be caused by a failed tensioner or an inaccurate tensioning process throughout a timing belt replacement.

7. Fuel Pump Leak

Of course, a camshaft gear that has drifted on the camshaft can cause similar symptoms as a slipped timing belt, but it is more challenging to diagnose.

That said, even if the timing is off, a slipped gear will enable the timing points to line up.

8. Problem With Fuel Injection Sensor

Fuel injectors need a certain amount of pressure to inject the correct fuel into the combustion engine chamber.

That said, the sensor connected to the engine control unit interacts with the fuel injector.

The sensor measures the quantity of pressure in the fuel injector and sends this data to the engine control unit. Then, this computer adjusts the pressure appropriately.

However, if the fuel injector sensor fails, the engine will not get the correct amount of fuel for proper combustion and could result in a starting car that dies immediately.

9. Faulty Carburetor

Carburetors are found in older vehicles that lack electronic fuel injection, and they are in charge of properly adjusting the air-fuel ratio to achieve efficient combustion.

Therefore, if your vehicle has a bad carburetor causing problems for a specific reason, the air/fuel ratio will most likely be off.

10. Poor Ground Strap

A faulty ground strap could cause a slew of electrical problems. In addition, you may encounter several irrelevant codes.

Therefore, specific systems could work intermittently or exhibit erratic behavior, and your vehicle may stall at any time in some cases.

So, if your engine starts, dies, and the battery light illuminates, the battery illumination may be a symptom rather than the cause. First, check to see if all main grounds are tight and clean.

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Of course, repairing a faulty foundation is usually inexpensive and straightforward. However, the problem is frequently in electrical testing.

If you’re trying to locate and replace bad ground, an engine wiring diagram and a multimeter would be your best friends.

11. ECU (Engine Control Unit) Problem

An engine control unit (ECU), engine control module (ECM), or powertrain control module (PCM) is the computer that manages the vehicle’s main engine parameters and programming.

With that, although a malfunctioning ECU is far less prevalent than a ground strap or wiring harness issue, the ECU can stop responding and cause a stall.

In addition, an ECU failure is often associated with various electrical system failures, such as incorrect or missing sensor readings.

One possible problem is the inability to control the fuel injection system effectively. As a result, it may cause issues with maintaining the vehicle operating after you start it.

To know more, you can also read our posts on why your car pulls when you brake, why your Dodge Ram shuts off while driving, and why your fuel gauge fluctuates.

Conclusion

A stall instantly after startup can have a variety of causes. So, to simplify the diagnostic process, you can narrow the problem to a single system or part.

Also, know that it’s helpful to have an online forum or a repair manual for your particular make and model on hand when troubleshooting.

In addition, some automobiles are more susceptible to specific issues, and discussion boards can help you identify such or simply bring your vehicle to your trusted technician.

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