Most of the most modern cars still run on internal combustion engines - that is, principles more than 150 years old. Despite all the electronic, intelligent stuffing, engines of all manufacturers are still susceptible to typical ICE diseases and problems. One such problem is the rich fuel mixture, which can make even a modern injection-powered car look like a self-propelled sidecar of the second half of the 19th century.
Signs of engine running on a rich mixture
Symptoms of this problem are difficult to ignore, and it is impossible not to notice them at all, regardless from driving experience. If your car engine runs on a rich fuel mixture, you will notice a number of unpleasant signs:
- pops and shots from the muffler;
- black or gray smoke coming out of the exhaust pipe;
- the “Check engine” icon on the dashboard is lit;
- read error P0172 detected;
- dips in dynamics - the car seems to stumble;
- fuel consumption increases significantly;
- in advanced cases, the car may not start at all.
Of course, with such problems, the car is almost impossible to operate. Many car owners, especially inexperienced ones, are very frightened of these symptoms and consider it a serious breakdown, which will be expensive to fix. In fact, everything is much simpler and more prosaic, and it can be expensive just to ignore the problem of a rich mixture for a long time.
What is a rich mixture
The very name of the internal combustion engine says that inside the engine, in its cylinders, fuel is burned. The process of burning something, as we know from the school curriculum, is the combination of molecules of something with oxygen molecules. Therefore, the engine needs a constant supply of air to operate. The problem is that there is only 20% oxygen in the air, and the oxygen molecules themselves are much smaller than gasoline molecules, so that for a full combustion, almost 15 times more air is needed than the fuel itself.
A rich fuel mixture is formed when this ratio is violated for some reason - more gasoline is supplied than needed. This is not good, because gasoline no longer burns out completely - it simply does not have enough oxygen to do this. Excess fuel is discharged from the cylinder together with the exhaust gases into the exhaust system. Because of this, the engine loses some part of the power at each stroke, it literally starts to choke. In some cases, gasoline can simply fill the cylinders, and then it will not be able to burn at all.
See also : What is an injector in a car
Reasons for the formation of a rich mixture
Most often, a rich mixture is formed not due to the fact that more fuel is supplied than necessary, but due to the fact that less air is supplied than necessary. The most common and common reason is a clogged air filter. Alas, many motorists forget that some components need to be replaced regularly, even if they look like new. The air filter is one of such units; it needs to be changed at least every 30 thousand kilometers, and even more often on powerful cars.
A malfunctioning air pressure sensor can also “cut off” the air supply. Together with it, a fuel pressure sensor works, which can also supply underestimated data to the electronic engine control unit. Based on them, the block begins to pump more fuel into the cylinders, enriching the mixture. She, as we learned above, impairs power and dynamics, the control unit does not like this, and it supplies even more gasoline. Hence - a greatly increasing fuel consumption.
The reason for the rich fuel mixture may also be hidden in the electronic engine control unit itself. These may be errors in his program, but also incorrect changes made to it. Self-taught craftsmen and simply unskilled craftsmen "tune" the control unit, deliberately increasing the proportion of fuel in the mixture. This can achieve a small increase in power, but it is much easier to upset the balance and achieve the opposite result.
The fuel pump can also violate the proportions of gasoline and air, pumping much more fuel into the system than is needed. And the most difficult reason to determine is the malfunction of the injectors in the cylinders. They can become clogged or deformed, and then the balance of the fuel-air mixture can fluctuate in any direction.
See also : Causes of lean mixture
Consequences of driving on a rich mixture
Driving on a rich mixture will do nothing good. If the problem is not resolved in time, this can lead to the following consequences:
- burnout and other damage to the muffler and catalyst, becausethe ejected fuel begins to burn out in the exhaust system - hence the black smoke, pops and shots;
- an oily sludge forms on the walls of the engine exhaust system, which clogs it, and after a long time, a complete cleaning of the system may be required;
- the percentage of harmful impurities in the exhaust gases increases sharply, which harms the environment and reduces the catalyst resource;
- Unpredictable dips in dynamics can be very dangerous for you and for other road users.
So at the first signs of enrichment of the fuel mixture, it is better to immediately visit a car service. Moreover, the problem is very quickly and easily determined by the on-board computer memory scanner - it displays error P0172. Also, in many cases, repairs are inexpensive and fast enough..