You can always notice a sputtering engine. In most cases, the engine might be failing, or it simply does not sound like it is operating at full capacity.
Sputtering indicates that the engine is not fully combusting. It might indicate a minor issue or an effect of a more serious engine, fuel system, or exhaust system fault.
Low-powered vehicles often sputter because of poor fuel systems. The issue is caused mainly by malfunctioning fuel pumps, fuel filters, or fuel injections. Alternatively, the problem could be caused by a defective spark plug or an issue with the ignition system coils.
This article will go through some of the most typical reasons why a car sputters while starting after getting gas.
Why Does Car Sputter When Starting After Getting Gas
What makes my car sputter after filling up with gas? A car sputters after filling up the tank because of fuel filter, injectors, or fuel pump issues.
The three parts are connected such that if any of them becomes clogged with dirt or debris, the whole fuel system fails indefinitely.
However, the most prevalent cause of car sputtering is a faulty fuel pump.
Issues with the Fuel System
The most common reason for a sputtering engine is a faulty fuel system-injector, pump, and filter.
All three key parts ensure that fuel flows easily from the fuel tank to the fuel injectors and then pumps evenly into the engine.
The process creates the ideal mixture of fuel and air for combustion, which powers your car.
Because the fuel filter, injectors and pump are all part of a single integrated system, clogging one component will lead to the failure of the other components.
This might result in sluggish engine performance or even engine failure.
Automotive experts often recommend an annual fuel system cleaning.
However, it is important to check your owner’s manual to see if a yearly cleaning is adequate or if your car requires more regular service.
Incorrect Ratio of Air to Fuel
A gasoline engine requires the proper air-to-fuel ratio to function properly. The worst errors happen when the mixture is either too ‘lean,’ meaning there isn’t enough fuel, or too ‘rich,’ meaning there is too much fuel. In such cases, the system may shut down.
When the mixture is too lean, there isn’t enough fuel to ignite, and if it’s too rich, the mixture cools down too much to ignite.
At 3,000RPM, there are 50 revolutions per second, and the charge has to ignite in around 1/20th of a rotation, so there’s about 1/1,000th of a second to do it.
Even though gasoline is highly flammable, there is a limit to what can happen in 1/1,000th of a second). There will be no power for those revolutions if there is no ignition.
More air is given to the gasoline engine when you push down the gas pedal and at the same time, the engine must release the amount of fuel correctly.
Did you know that older cars had a cable from the pedal to the throttle – flapper valve controlling airflow – and the valve would swing wide open?
However diesels are completely different.
Carburetors were renowned for sputtering, and in the 1960s, flooring the accelerator pedal was a guaranteed way to make the car sputter.
If your carb was one of those, you learned not to floor the accelerator pedal.
Most modern cars have their throttle valve and the fuel injection controlled directly by the computers.
There is much greater control of the fuel mixture using the computerized direct injection, and it is unusual now that the engine will ‘misfire,’ causing the sputtering reaction.
If it does, it signifies something is amiss.
Faulty Catalytic Converter
A faulty catalytic converter could be causing the engine to sputter.
The catalytic converter helps reduce pollutants produced by your vehicle.
This component, which is part of your vehicle’s exhaust system, converts toxic molecules such as carbon monoxide, nitrous oxide, and hydrocarbons into less hazardous compounds like carbon dioxide and water.
Consult a professional mechanic to determine whether the sputtering is caused by the catalytic converter and, if so, repair or replace it if needed.
Whatever is causing the sputtering should be addressed as quickly as possible to avoid costly, long-term damage to your vehicle since many of these faults can lead to engine failure.
Issues with Spark Plugs
Sputtering might also indicate that one of the most important components of your engine, which is the spark plug, needs to be replaced.
The air-fuel mixture in your car’s engine is “sparked” by spark plugs, which send power flowing through your car.
Consequently, you may be unable to start your vehicle if the plugs are dirty or otherwise not functioning properly.
Faulty Mass Airflow Sensor
A dirty mass airflow sensor might also cause a sputtering engine.
As part of the fuel injection process, the sensor maintains track of the temperature and mass of the air flowing into the engine.
A clogged sensor can cause various issues, including poor engine performance and decreased gas mileage.
Car Sputters When Starting After Getting Gas Other Possible Causes
I’m assuming “after getting gas” means after you’ve filled your car with car at gas station.
If your car didn’t sputter before buying gas and then sputters afterward, the most obvious reason you refilled your car with water contaminated gasoline.
It is better to choose a different gas filling station in such instances.
When you fill your tank with gasoline contaminated with water, the water settles at the bottom of the fuel tank.
You will notice that the car sputters for a few miles and when the water runs out and you’re left operating on gas from the top level, which has no water; thus, the sputtering stops. On your next fill-up, it all starts over.
Final thoughts Car Sputters When Starting after Getting Gas
If your car sputters when you step on the gas pedal, there is a problem. It could indicate a more significant problem, such as an issue with the fuel or exhaust system, especially dirty or worn-out parts.
Whatever is causing the sputtering, it’s necessary to fix the problem as quickly as possible to avoid costly, long-term damage to your vehicle. Many of these faults can lead to engine failure.
Hi I’m Marshall based in 1478 Doctors Drive Santa Monica, CA. I’m your DIY Car Repairman with more than 5 years experience in automobile repair, a skill I learned from my old man.
I started this blog to share my experience on both simple and technical aspects of your car.