11 Possible Causes of Why Car Sputters When Starting After Sitting

If you are driving and the engine of your automobile begins to sputter, the first reason for worry may be that there is not enough gasoline in the tank.

On the other hand, if the gasoline gauge on your vehicle is reading full, this might be an indication of more engine issues. For instance, if the fuel filter has got clogged, this would prevent gasoline from reaching the combustion chambers.

If the issue is not addressed and fixed as soon as possible, it may cause more harm to the engine.

In this article, we will discuss the potential causes of why a “car sputters when starting after sitting”.

11 Reasons Why Car Sputters When Starting After Sitting

If the engine of your vehicle is sputtering, the problem is probably with the fuel system. This is by far the most frequent cause. A faulty fuel filter, fuel pump, or fuel injector are all potential culprits in this scenario. Spark problems might also be the reason, and they can be brought on by faulty spark plugs or ignition coils.

Even if these are not all of the potential reasons, it’s a good place to start looking. The following is a more in-depth summary of the most prevalent factors that contribute to a sputtering engine.

1. Weak Battery

It’s possible that the first issue is that your battery isn’t strong enough. If the battery is only charged to the point where it is able to turn over the vehicle, then the engine may stutter before it finally begins moving.

Because once the engine is operating, it does not need as much power from the battery, which is why it is possible for it to reach an equilibrium state. In addition, the alternator will begin to charge the battery as soon as the engine is turned over and running.

If the sputtering was caused by a poor battery, then it will probably only happen once, since the battery will be charged after being driven for a while. When you try to start the vehicle it may continue to splutter if the battery is not capable of maintaining a charge.

Turning on your headlights before starting the vehicle is one way to determine whether or not the battery is weak; if the lights are faint, this indicates that the battery is weak. You might try testing the battery or charging it with the appropriate maintainer to determine if it needs to be replaced. If the sputtering is caused by low battery power, changing the battery will fix the issue.

2. Exhaust Leak or Leaking Gaskets

Next on the list of potential causes of sputtering is a leak in the exhaust system. The location of the exhaust leak is undetermined. Either the manifold or farther along beneath the automobile might be the location of it.

Leaks in the exhaust system are not only annoying but also hazardous since the exhaust is quite hot and may melt the plastics that are nearby or even go into the car. Sputtering may also be caused by leaking gaskets on the engine, which can influence the fuel mixture and lead it to become unstable.

Finding leaks in the exhaust system may be accomplished by first attaching a blower to the tailpipe and then dousing the exhaust system with water. Any location at which bubbles form indicates the presence of a leak, which must be repaired.

3. Improperly Functioning Spark Plugs

Spark plugs are absolutely essential in order to provide the required ignition for the air-fuel combination. However, with time, plugs wear out and become unable to perform at their optimum.

In this scenario, you are going to have a lot of unburned gasoline, which will cause the engine to sputter and create misfires. In order to forestall incidents like this one from occurring, the spark plugs should be changed according to a predetermined schedule. If you haven’t already done so at the time, you should do it now since spark plugs that aren’t working properly might make your engine stutter.

Take out your spark plugs and give them a visual examination; if they seem to be old and dusty, it may be time to replace them. In addition to that, you should think about inspecting the ignition coils, as they can be the root of the problem.

4. Clogged Fuel Filter

It is the function of the fuel filter to filter the fuel before it is delivered to the fuel injectors and subsequently goes into the engine. If the fuel filter is blocked, it may cause the engine to have too low of fuel pressure or it can cause the fuel injector to get clogged.

Because low fuel pressure will cause the engine to operate extremely leanly, it is possible that the engine could sputter as a result.

It is recommended that the gasoline filter be changed at regular intervals, and if you haven’t done so during the most recent maintenance, it needs to be changed. Fuel filters are often simple to change and do not incur a disproportionately high cost.

5. Faulty Fuel Pump

The gasoline pump is subject to the same requirements as the fuel filter in this regard. In the event that the fuel pump fails, the resulting loss in fuel pressure will cause the engine to operate with an excessive amount of excess air-fuel ratio.

Installing a manual fuel pressure gauge to check the fuel pressure is the simplest approach to find out if it is working fine.

If the fuel pressure in your vehicle is much lower than normal, there is most likely an issue with either the fuel filter or the fuel pump.

6. Vacuum or Intake Leak

If there is a leak at the hoses that connect to the intake manifold or intake manifold itself, it may result in a mixture that is too lean, which may cause your automobile engine to sputter while it is idling.

Using an EVAP smoke machine is the quickest and most efficient technique to locate the issue. Since it is quite unlikely that you have one at home, therefore you may also attempt to discover leaks by listening for high-pitched sounds around the engine compartment when the engine is running in idle mode.

You may also try spraying soap over the intake hoses to see if any leaks are brought to your attention.

7. A Mass Airflow Sensor That is Dirty or Has Been Damaged

In order for the combustion chamber to function properly, there must be the appropriate quantity of fuel and air. The flow of these components is constantly monitored by an onboard computer that is standard in modern engines. The mass air flow sensors are responsible for ensuring that the combustion chambers get the appropriate volume of air at all times.

When the sensors are completely clogged with bits of dirt, they are no longer able to provide the ECU with accurate information. Because of this, the engine control unit will spray either an excessive amount or an inadequate amount of gasoline into the cylinders, which will result in the engine sputtering.

It is possible to clean the mass airflow sensor by removing it and then cleaning it with an electronic cleaner in a cautious manner.

8. Dirty Fuel Injectors

Fuel is sprayed into the combustion chambers of each cylinder by the fuel injectors. After that, this is combined with air, and the spark plugs set the mixture ablaze.

Small filters are built right into the fuel injectors, and those filters may get clogged if the fuel filter is not functioning as it should be. Because of this, the fuel injector may spray too little fuel into the combustion chamber, leading to a misfire in the cylinder and perhaps causing the engine to sputter.

These minuscule filters can be swapped out for new ones, and just about any workshop should be able to do it for you.

9. Faulty Ignition Switch

If the ignition switch is not functioning properly, it is possible that it is not giving the correct signal to the engine, which prevents the engine from turning over completely.

Because of this, the engine can splutter when you try to start it because the correct amount of charge isn’t being applied. However, this is one of the things that should be checked very late in the process because if the problem is with the ignition switch, then it is quite probable that the vehicle will not start at all.

10. Malfunctioning Catalytic Converter

When it comes to eliminating dangerous pollutants from the exhaust, the catalytic converter is an essential component. If the catalytic converter is too old, it will get clogged, and it also has the potential to split apart internally, which will cause the exhaust pathway to become blocked.

Because of this, your engine will experience excessively high back pressure, which will result in the engine beginning to sputter.

You may attempt to clean the catalytic converter by using a cleaner designed specifically for that purpose.

If the catalytic converter in your vehicle is not functioning properly, you may detect a powerful odor similar to that of rotten eggs.

11. Faulty Oxygen Sensors

Oxygen sensors are in charge of controlling the amount of fuel that is introduced into the combustion chambers. If the oxygen sensor is broken, the mixture will either be too rich or too lean.

Because of the dirt that settles on the oxygen sensors over time, they are unable to provide the onboard computer with accurate data beyond a certain point. Because of this, they either emit an excessive amount of gasoline or an inadequate amount of fuel.

To diagnose the faulty oxygen sensors you require a diagnostic scanner.

Where to Begin?

Given all of these potential reasons why car sputters when starting after sitting, how can you possibly know where to begin when attempting to resolve the issue? The majority of these problems, however, will cause the “check engine” light to illuminate.

If your vehicle’s check engine light is on, you should consult an OBDII scanner in order to determine what the problem is. After that, you are free to investigate the significance of the code and go to work resolving the issue.

The only thing that probably won’t transmit code is a weak battery, so if you don’t have a code, start with the battery first.  Everything else will result in a code, and from there, you will be able to determine what needs to be fixed.

The Bottom Line

It’s frustrating when your automobile sputters and jerks when you try to start it since there are so many things that may be wrong with it. Fortunately, the majority of the repairs are ones that can be done at little cost.

Simply read the trouble code to find out what the issue is, and then either repair or clean the faulty component.

Sputtering cars get poor gas economy and may even introduce harmful vapors into the inside of the vehicle, so it is imperative that you address the problem as soon as you possibly can. You are fortunate that you have gained all of the necessary knowledge about the “car sputters when starting” problem when you attempt to start your automobile.