“My car starts but wont stay running for long. What should I do? You probably have found yourself in such a situation. There are times when a vehicle runs for seconds and then shuts off by itself, or it can die while driving and won’t start.
This may be a result of different failures in the parts of the vehicle. Identifying the exact possibility of this failure may be challenging when you do not understand the car systems.
Many people have reported having similar failures such as “my 2000 BMW starts but won’t stay running” or “my car starts then die unless I give it gas.” This article is here to give solutions to complaints and answer all the questions related to these kinds of problems.
Causes Of Car Starts But Won’t Stay Running
As we stated, this failure involves many parts. You need to do several checks and fixes to know the exact causes of the faults and how to deal with them the right way.
#1. Ignition System Problems.
The 3 core elements for the car to start and run are fuel, spark, and air. If these three elements are available in the correct ratio, then the car will run smoothly and will not stop.
If one of the three elements fails to decrease or increases slightly, the ratio changes and the car will not have a smooth running.
After a while, it will shut off due to a bad spark or since the fuel support is not enough to sustain the engine and keep it running. This is what causes the car to start and then die when cold.
#2. Bad Canister Vent Valve.
The canister vent valve is part of the (EVAP) which is the evaporative emission control system. Its role is to route the vapors produced from the fuel and get them back to the canister and from the canister to the intake manifold.
It then goes to the combustion chambers and gets fired by the spark plugs. The benefit of this system is to reduce fuel consumption. If this system fails, the car becomes unstable when idle and it turns off immediately after starting up.
#3. PCV Valve Failure.
PCV (positive crankcase ventilation) valve is a valve designed to purge blow-by gases in the engine from the heating of the oil. It is resent to the intake manifold for lubricating and re-burning purposes.
The PCV systems use a very tiny valve to get this job done. This valve goes open when purging the overloaded pressure.
When this valve is defected and remains open, it results in an overflow of air streams into the intake manifold when idle or accelerated, causing the car to stall.
#4. TPS Fault.
TPS (throttle position sensor), is the sensor responsible for sending the throttle position to the ECU (engine control module).
The importance of this signal is that ECU calculates the quantity of fuel to be provided to injectors to keep the right ratio between air and fuel in the mixture.
When the throttle position sends the wrong signal to the ECU the fuel quantity delivered to the injector’s rail will be wrong; thus, the car may stall on idle. And you will notice that car starts but won’t stay running unless the foot is on gas.
#5. ECT Sensor.
This component helps the engine to protect itself and prevent its performance from getting by the engine temperature.
The ECT (Engine Coolant Temperature) sensor is here to send information about the engine’s temperature to the ECU to adjust the mixture of air and fuel.
When the ECT sensor is faulty, it sends wrong or false information about the temperature of the mixture, making it hard for the ECU to provide the right fuel quantity.
The combustion will not be right, and this will cause roughness while driving the car and sometimes lead to stalling.
The worst side of this kind of failure is that if the engine overheats the fans do not work at maximum speeds since they don’t have signals that the temperature is too high.
#6. EGR Valve Defect.
The EGR (Exhaust Gas Recirculation) is a system that recirculates part of exhaust gases back into the engine to reduce the temperature of the combustion chamber by getting this small portion of the exhaust gas back into the intake manifold.
It is usual for the EGR valve passages to get stuck and blocked by the carbon build-ups. This prevents the valve from closing, thus making an extra air stream inside the engine that will cause stall and instability while idle.
#7. Catalytic Converter.
The catalytic converter’s role in the car is to revise, correct, and evaluate the work of the engine. It makes sure that the combustion is running well.
The catalytic converter is usually attached to an oxygen sensor. The role of this sensor is to analyze the exhaust coming out of the combustion chambers and detect the percentage of oxygen in it.
Depending on this info it corrects the air to fuel mixture to make successful combustion. The combustion is just balanced, and it’s neither lean nor rich.
Therefore when the catalytic converter has a defect or is made of low quality, the sensor will not give accurate readings, and the air to fuel mixture will be affected negatively.
#8. Wrong Injector Pulses.
If you always feel that a car starts then sputters and dies, it could be as a result of wrong injector pulses. As we talked about before that to have successful combustion, three elements must be provided in specific quantities.
They include the spark through the spark plugs, air going into the engine through air ducts and passing by the air filter, and finally the fuel supplied into the engine by injectors. Injectors perform this process via pulses.
When the ECU gives a signal to the injector, it magnetizes the plunger and sprays fuel into the intake manifold or in the cylinder directly in some systems which are the GDI.
Therefore, if these injectors are failing to give the right pulses, giving pulses at the wrong timing, or have a defect like over bleeding fuel, it prevents perfect combustion of this unsmooth running.
#9. CMP\CKP.
It is either called Camshaft Position Sensor or Crankshaft Position Sensor. You will never have a balanced performance out of your car if you have a defective camshaft position sensor or crankshaft position sensor.
The work of the sensors is defining the timing and the spot of the crankshaft and camshaft. They also define the degree to of the valve opens to provide the air and fuel mixture to the combustion chambers.
All this info is sent to the ECU for processing and analysis. It then decides on when to ignite the spark and when to spray the specific quantity of fuel. It also decides on the depth of the valve opening to be adjusted depending on the information.
Symptoms of a Car Starting but Not Staying Running
#1. Engine Stalling Immediately After Starting.
One of the most common of a car starting but not staying running is the engine stalling immediately after it is started. This can be quite frustrating and may leave you stranded. When the engine stalls, it abruptly shuts off and the car comes to a stop.
This can happen within seconds of starting the engine or after a short period of driving. It is important to pay attention to any warning signs or unusual noises that occur before the engine stalls, as this can help pinpoint the underlying issue.
#2. Rough Idle Before Shutting Off.
Another symptom to watch out for is a rough idle before the car shuts off. When the engine is running, it should maintain a smooth and consistent idle.
However, if you notice that the engine is idling roughly or has a shaky idle before shutting off, it could indicate a problem.
This rough idle can be felt through vibrations in the steering wheel, floor, or even the entire car. It is important to address this issue promptly, as it can lead to further damage if left unresolved.
#3. Sputtering or Misfiring Engine.
A sputtering or misfiring engine is another telltale sign that your car is starting but not staying running. When the engine misfires, it means that one or more cylinders are not firing properly.
This can result in a sputtering sound, jerky movements, and a lack of power. You may also notice a decrease in fuel efficiency and acceleration.
Ignoring a misfiring engine can lead to more serious issues, such as damage to the catalytic converter or other engine components.
#4. Loss of Power or Acceleration.
If your car starts but then loses power or acceleration shortly after, it is a clear indication that something is amiss. Loss of power can manifest in various ways, such as sluggish acceleration, difficulty maintaining speed, or a complete lack of power.
This can make it challenging to drive the vehicle safely and can put you at risk on the road. It is crucial to address this issue promptly to prevent further damage and ensure optimal performance.
#5. Check Engine Light Illuminated.
When a car starts but does not stay running, the check engine light is often illuminated on the dashboard. The check engine light serves as a warning that the engine or emission control system is experiencing a problem.
It can indicate a wide range of issues, from minor to more significant problems. When the check engine light comes on, it is essential to have the vehicle diagnosed as soon as possible to identify the specific issue and take appropriate action.
Diagnostic Steps : Car Starts But Will not Stay Running
#1. Initial Inspection.
Begin with a visual inspection and diagnostic scan.
- Visual inspection: Look for obvious signs of damage or wear.
- Check engine light: A lit check engine light can provide valuable error codes.
- Error codes: Use an OBD-II scanner to retrieve error codes.
#2. Fuel System Diagnostics.
Check the fuel system for any issues.
- Fuel pressure test: Measure the fuel pressure to ensure it’s within the correct range.
- Fuel pump relay: Test the relay to ensure it’s functioning properly.
- Fuel filter check: Inspect and replace the fuel filter if necessary.
#3. Ignition System Diagnostics.
Examine the ignition system components.
- Spark plug test: Check the condition of the spark plugs.
- Ignition coil test: Test the ignition coils for proper function.
- Distributor cap inspection: Inspect the distributor cap for wear or damage.
#4. Air Intake Diagnostics.
Assess the air intake system.
- Air filter inspection: Check and replace the air filter if needed.
- MAF sensor cleaning: Clean the mass airflow sensor to ensure accurate readings.
- Throttle body cleaning: Clean the throttle body to ensure proper air intake.
#5. Electrical System Diagnostics.
Ensure the electrical system is functioning correctly.
- Battery voltage test: Check the battery voltage to ensure it’s holding a charge.
- Alternator test: Test the alternator to ensure it’s charging the battery.
- Wiring inspection: Inspect the wiring for any signs of damage or corrosion.
How to Fix the Problems?
If you can get the car started but are having trouble keeping it running, it’s time to start the diagnosis process. You don’t want to keep running your car this way or it could leave you stranded.
Here are some of our best suggestions as professional mechanics.
#1. Read Trouble Codes.
When a fault occurs within the sophisticated car systems, a code gets set in the computer. To alert you, the Check Engine Light comes on the dashboard. With a compatible scanner, you can read these OBD-II trouble codes.
Many codes are generic across multiple manufacturers. However, there are some that are specific to a particular brand.
For that reason, it’s best to research the information with our trouble code library. Once you know what’s wrong, you will be able to apply the appropriate fix.
#2. Check Fuel Pressure.
There are a couple of ways to determine if fuel pressure is low. You can use a fuel pressure gauge to see what’s going on. These connect easily to the fuel rail.
Fuel pressures vary by car. You won’t know what’s normal unless you look at the specifications from your car manufacturer. You can find this information online or check out the factory service manual to learn more.
If the fuel pressure is low, your next step is to figure out why. It’s probably either the fuel pump, pressure regulator or a clogged fuel filter.
#3. Check Immobilizer Symbol On Dashboard.
Take a look at your dashboard to see if the anti-theft system is activated. Normally, a key symbol appears, showing that the system is enabled.
If you put your key in the lock or ignition, the symbol should turn off automatically because it recognizes that you are the owner with the right key.
If the system stays illuminated, there could be something wrong with the key. You may have to get it replaced at a dealership or through a locksmith.
With aftermarket systems, it’s common to have an issue with the alarm or the wiring. This is even more probable if an inexperienced technician puts the system in.
#4. Check for Vacuum Leaks.
To start, take a look under the hood and see if anything obvious stands out to you. There could be a torn or disconnected vacuum line that needs to be repaired. If nothing obvious is seen, you have to start diagnostics.
Perform a smoke test where you pump smoke into the intake. The smoke will come out of holes in the system, showing you where the leak is.
#5. Clean and Reset the Throttle Body or IAC.
With a special cleaner, you can remove any contamination from the throttle body and IAC. If that doesn’t work, you need to perform some more advanced diagnostics.
A multimeter helps you test the throttle body and IAC. Check the wiring diagram in your factory service manual to get to the bottom of the problem. You can also follow the reset procedures to see if that resolves the issue.
#6. Contact A Professional.
As a last-ditch effort, you may want to take a look at the car battery and ignition system to see if anything else is wrong. However, you may be branching into more advanced territory if you aren’t sure what you are doing.
If anything feels too difficult for you, it’s best to reach out to a professional technician. You don’t want to mess with these sophisticated systems unless you know what you are doing.
Preventive Maintenance
To lessen your chances of your car dying immediately after starting, performing regular preventive maintenance is needed. Here are a few things you can do:
- Check Your Fuel System: Make sure your fuel filter, fuel pump, and injectors are clean and functioning properly. Regularly replacing the fuel filter can help prevent clogging and ensure proper fuel delivery.
- Inspect the Ignition System: Keep an eye on your spark plugs, ignition coils, and distributor cap (if your car has one). Replace them as recommended in your owner’s manual or whenever you notice any wear and tear.
- Monitor the Air Intake System: The idle air control valve (IAC) and mass airflow sensor (MAF) play important roles in regulating the air-fuel mixture. Keep these components clean and replace them as needed to prevent any issues.
- Examine the Timing Belt or Chain: A slipped timing belt or chain can cause the engine to stall (among other things). Regularly inspect it for wear and replace as necessary or according to the manufacturer’s recommended interval.
- Check for Vacuum Leaks: Leaks in the vacuum system can trigger engine stalling. Be sure to inspect hoses and connections for any sign of wear or damage.
- Stay Up-to-Date With ECU Updates: Keep your ECU software updated, as manufacturers often release updates to improve engine performance and fix potential issues.
- Test Your Battery and Charging System: Ensure your battery is in good condition, as a weak battery can cause starting issues. Additionally, make sure your alternator is keeping the battery charged.
FAQs.
Q: Why is my car shaking and then dying?
There could be a lack of fuel or an ignition problem. It’s also possible that you are dealing with a vacuum leak or have just put in low-quality fuel. Otherwise, the throttle body or IAC may be to blame. The only way to figure out what’s wrong is to diagnose the systems.
Q: Why won’t my car stay running without my foot on the gas?
The most obvious answer is that fuel isn’t getting into the system. However, other causes include a vacuum leak, ignition problems or a malfunction with the throttle body.
Walk through some diagnostic steps to determine where the problem is coming from before the car breaks down.
Q: Why does my car cut out when I take my foot off the accelerator?
There seems to be a fuel system issue that is causing a lack of pressure. However, ignition problems, vacuum leaks and throttle body malfunctions can cause some similar symptoms as well.
With some simple diagnostics, you can figure out what’s wrong so it can be repaired.
Q: What are the signs of a clogged fuel filter?
The car may be hard to start because fuel can’t get to the engine. While the car is running, it could misfire or have a rough idle. It’s also possible that the car will stall, leaving you in a dangerous situation.
Additionally, you could hear strange noises coming from the fuel pump, especially if contaminants are in the system.
Q: Why does my car only start when I give it gas?
There’s something wrong with the air-fuel balance in the engine or it’s not igniting properly. There needs to be a perfectly balanced amount of air and fuel, plus it must be ignited at just the right time.
The advanced systems in the car handle these tasks until something malfunctions and breaks.
When the car doesn’t stay running, it’s a scary situation. Even as professionals, this situation is enough to cause alarm for us.
However, you don’t want to panic when trouble starts. Instead, you want to take decisive actions and carefully get off the road into a safe location.
You can walk through our guide to figure out what’s causing the problem and get back on the road without any more issues. If the situation seems too complicated for what you are used to, please reach out to a professional for more support.
Final Words
If your car starts then dies after a few minutes, or even seconds, you can be sure to find the reason for the fault in this article. The secret to ending this problem from the root has a proper diagnosis.
I, therefore, suggest that you use the car-supported diagnostic tool to get full sensors scan, complete programming, and calibrating abilities.
Finally, if you feel so confused about the problem, it is always a good idea to ask an expert for a solution. You will save time, and money, and get your car recovered easily and hassle-free.