Car Idles Fine But Dies When Given Gas: 7 Common Causes
Car problems can be difficult to handle, especially if we don’t know what is going wrong. Car problems can also become expensive, even in the diagnostic process. It is often a good idea to understand a little bit of what is happening under the hood to help see symptoms of common problems.
Car Idles Fine But Dies When Given Gas
The most common reasons that a car would suddenly die when you press the gas are:
- An issue with the air control valve
- Clogged fuel filter
- Vacuum issues
- Broken airflow sensor
- Throttle bore
- Exhaust gas recirculation
- A broken carburetor
With these common causes in mind, it is important to understand what these parts are, what these parts do, preventative measures to keep these parts in good repair, and repair options.
1. Air Control Valve
The air control valve is a part of the car that moderates the engine functioning when idling. This valve moderates how much air goes inside your vehicle. When a car starts to idle, you don’t need as much airflow as you do when you are actively driving.
When you press the gas, you open the throttle plates that allow the airflow to go inside the engine and cause the reactions needed to make the car move and the speed of it increase.
Thus, if something is wrong with the air control valve, your car will not be able to move when you press on the gas. In older vehicle models after around 70,000 miles, the valve can get dirty and impede the function of the part and make your car stall.
Luckily, there are some simple potential fixes. You can easily fix this by using a shop towel and a carburetor cleaner to clean it off by hand.If you are not comfortable doing this, there are videos online showing the process and professionals that can do it as well.
2. Clogged Fuel Filter
A fuel filter is a filter that moderates debris and other stuff entering the engine while letting fuel pump into the engine. If the filter gets clogged, which is common and happens easily, it can cause your car to not function properly.
The costs of fixing it can be costly. However, if a person is proactive and replaces the filter occasionally, it is not as expensive.
Newer models don’t typically have a filter to replace, they have a strainer that isn’t replaced until it breaks.
The best thing to do before you go to the effort and spend the money to replace the fuel filter is to get readings with a vacuum gauge and a fuel pressure gauge. (Source)
3. Vacuum Issues
The engine uses different parts that create a vacuum inside the engine that helps monitor the air and gas levels in the engine.
If something happens that impacts those levels, the car will stop working. This can be as simple as a vacuum hose having a leak or cracks in other parts of the engine.
You can sometimes tell if a car is experiencing a vacuum leak if the car makes a whistling noise before it stalls. Vacuum issues can be simple and inexpensive to fix if it is a simple leak.
If it is more complex or a part is cracked, a person can end up paying over a thousand grand.
4. Airflow Sensor
The airflow sensor is a sensor that measures how much air is heading into the engine. It is nearby the air filter. This is important to note because it helps keep the air and gas amounts balanced and your engine functioning well.
Usually, if the sensor is misreading or not working at all, the check engine light will turn on.
But, either way, the car will probably need to go into the shop to get fixed.
5. Throttle Bore
The throttle bore is a part of the car that moderates the amount of air that is imparted to the engine from the accelerator pedal.
Similar to the air control valve, malfunctions can happen around 70,000 miles because the part becomes dirty. You can hand clean it yourself or get it fixed by a professional.
6. Exhaust Gas Recirculation (EGR) Valve
The EGR valve is a part of a diesel vehicle that controls how much exhaust air is brought back in through the intake.
This is important for the car to function because the exhaust air is high in temperature and can mess with the balance of air to gas in the engine. The best way you can take care of the valve is to use good fuel, keep the valve clean, and do normal maintenance.
If the carburetor is clogged, your car will idle but stall when you press on the gas pedal.
The carburetor allows fuel and air to mix so the engine can burn fuel. If the carburetor doesn’t allow the engine to burn fuel properly, your car can’t function properly.
When you press the gas pedal, you increase the amount of fuel your car needs to burn, which is why you won’t notice that there is a potential issue with the carburetor while your car is idling.
Luckily, it is easy to determine if your car’s carburetor is the issue. Simply take it out of the engine and determine if it is clogged or dirty. If it is clogged, clean the interior with a soft brush and cloth.
If the carburetor is extremely dirty or you aren’t able to remove the clog, purchase a new one.