Why do some cars stall after the tank is completely full?
- September 25, 2023
- 0
Sometimes a car poses unexpected puzzles for the car owner, breaking down for mysterious (at first glance) reasons. One of them has been pursuing car owners of completely
Sometimes a car poses unexpected puzzles for the car owner, breaking down for mysterious (at first glance) reasons. One of them has been pursuing car owners of completely different models and brands of cars for decades.
The problems we are going to talk about sometimes occur after filling up with gasoline. This happens as follows. A car with a half-empty tank arrives at a gas station. The owner decides that pumping fuel “below the neck” is a great idea. And fuel is added to a level where the gun begins to break down, cutting off the fuel supply. After the procedure is completed, the driver tries to start the car. The starter turns the engine, the engine, as they say, “seizes”, tries to start, but stalls, scaring the owner.
The next attempts, as a rule, are accompanied by pressing the accelerator pedal and the power unit reluctantly agrees to work. But only until the driver’s foot releases the accelerator. After a few kilometers in this mode, the “glitch” disappears – the engine stops stalling and continues to behave as if nothing had happened. It has been noticed that such incidents mainly occur in fairly warm weather – 25ºC and above.
The main suspects in the described situation are the bus of the engine power system and the valve that connects it to the intake manifold. We remind you that the adsorber is filled with activated carbon and connected to the fuel tank via a hose. This causes gasoline vapors to enter the unit and be absorbed by the “coal” instead of escaping into the atmosphere. When the engine starts to run, an area of low pressure forms in the intake tract. The adsorber valve opens and the gasoline absorbed by the activated carbon is sucked into the engine cylinders.
This is in theory. In practice the following can happen. Gasoline at gas stations is usually stored in underground tanks, so it does not heat up much even in extreme heat. The cool fuel is then brought to the surface and the fuel tank, sometimes heated to above 30ºC, is completely filled with it. And close the lid. Gasoline starts to warm up to outside temperature. The coefficient of thermal expansion is one of the largest among liquids: 0.00124. This means that 40 liters of fuel, warming up, for example, from 15ºС to 30-35ºС, adds about one liter in volume.
The expansion process takes place in a closed gas tank. Where does the ‘extra’ petrol go when the car is filled ‘below the neck’? That’s right – go along the pipeline leading to the adsorber. At the same time you squeeze fuel vapors in front of you. The driver, who has paid at the cash register, turns on the ignition. At the same time, the valve opens and a powerful jet of fuel vapor bursts from the adsorber into the intake tract and then into the cylinders – in addition to what is injected there at the command of the engine control unit. To burn these volumes, the engine runs out of air and stalls.
Then the “steering wheel”, trying to start the car, panic presses the accelerator pedal, forcibly opening the air valve. This provides the supply of additional oxygen and the engine works somehow. After some time, the supply of “excess” gasoline in the adsorber runs out and the car starts to function normally.
The problems we are going to talk about sometimes occur after filling up with gasoline. This happens as follows. A car with a half-empty tank arrives at a gas station. The owner decides that pumping fuel “below the neck” is a great idea. And fuel is added to a level where the gun begins to break down, cutting off the fuel supply. After the procedure is completed, the driver tries to start the car. The starter turns the engine, the engine, as they say, “seizes”, tries to start, but stalls, scaring the owner.
The next attempts, as a rule, are accompanied by pressing the accelerator pedal and the power unit reluctantly agrees to work. But only until the driver’s foot releases the accelerator. After a few kilometers in this mode, the “glitch” disappears – the engine stops stalling and continues to behave as if nothing had happened. It has been noticed that such incidents mainly occur in fairly warm weather – 25ºC and above.
The main suspects in the described situation are the bus of the engine power system and the valve that connects it to the intake manifold. We remind you that the adsorber is filled with activated carbon and connected to the fuel tank via a hose. This causes gasoline vapors to enter the unit and be absorbed by the “coal” instead of escaping into the atmosphere. When the engine starts to run, an area of low pressure forms in the intake tract. The adsorber valve opens and the gasoline absorbed by the activated carbon is sucked into the engine cylinders.
This is in theory. In practice the following can happen. Gasoline at gas stations is usually stored in underground tanks, so it does not heat up much even in extreme heat. The cool fuel is then brought to the surface and the fuel tank, sometimes heated to above 30ºC, is completely filled with it. And close the lid. Gasoline starts to warm up to outside temperature. The coefficient of thermal expansion is one of the largest among liquids: 0.00124. This means that 40 liters of fuel, warming up, for example, from 15ºС to 30-35ºС, adds about one liter in volume.
The expansion process takes place in a closed gas tank. Where does the ‘extra’ petrol go when the car is filled ‘below the neck’? That’s right – go along the pipeline leading to the adsorber. At the same time you squeeze fuel vapors in front of you. The driver, who has paid at the cash register, turns on the ignition. At the same time, the valve opens and a powerful jet of fuel vapor bursts from the adsorber into the intake tract and then into the cylinders – in addition to what is injected there at the command of the engine control unit. To burn these volumes, the engine runs out of air and stalls.
Then the “steering wheel”, trying to start the car, panic presses the accelerator pedal, forcibly opening the air valve. This provides the supply of additional oxygen and the engine works somehow. After some time, the supply of “excess” gasoline in the adsorber runs out and the car starts to function normally.
Source: Avto Vzglyad
Donald Salinas is an experienced automobile journalist and writer for Div Bracket. He brings his readers the latest news and developments from the world of automobiles, offering a unique and knowledgeable perspective on the latest trends and innovations in the automotive industry.
