What it is? Causes and consequences
Often engine problems arise due to the fact that the proportions of the fuel-air mixture are violated.
Ideally, one dose of TVS should include:
- 14,7 parts of air;
- 1 part gasoline.
Roughly speaking, 1 liters of air should fall on 14,7 liter of gasoline. The carburetor or injection injection system is responsible for the exact composition of the fuel assemblies. In different situations, the Electronic Control Unit may be responsible for preparing the mixture in different proportions, for example, when it is necessary to increase traction or, conversely, switch to a more economical consumption mode.
If the proportions are violated due to various malfunctions of the injection system, then you can get:
- poor fuel assemblies - the air volume exceeds the set value;
- rich TVS - more gasoline than needed.
If your car is equipped with a lambda probe, which we talked about on Vodi.su, then the on-board computer will immediately give errors under the following codes:
- P0171 - poor fuel assemblies;
- P0172 - rich air-fuel mixture.
All this will immediately affect the operation of the engine.
The main signs of a lean mixture
Main problems:
- overheating of the engine;
- mismatch of valve timing;
- significant reduction in traction.
You can also determine the lean mixture by the characteristic marks on the spark plugs, we also wrote about this on Vodi.su. So, light gray or whitish soot indicates that the fuel assemblies are depleted. Over time, spark plug electrodes can melt due to constant high temperatures.
However, a more serious problem is overheating of the engine and, as a result, burnout of pistons and valves. The engine overheats because lean gasoline with a high oxygen content requires higher temperatures to burn. In addition, all gasoline does not burn out and, together with the exhaust gases, enters the exhaust manifold and further into the exhaust system.
Detonations, pops, blows in the resonator - these are all signs of a lean mixture.
It is worth noting that although such serious problems await the owner of the car, the engine will still work. If the proportions of oxygen to gasoline change to 30 to one, the engine will hardly be able to start. Or it will stall on its own.
Lean mixture on HBO
Similar situations also occur in cases where a gas-cylinder installation is installed on the car. The proportions of gas (propane, butane, methane) to air should be 16.5 parts of air to gas.
The consequences of less gas entering the combustion chamber than it should be are the same as in gasoline engines:
- overheat;
- loss of traction, especially if you are moving downhill;
- detonation in the exhaust system due to incomplete burnout of gaseous fuel.
The on-board computer will also display a fault code P0171. You can get rid of the malfunction by reconfiguring the gas installation or changing the settings of the control unit map.
You also need to check the injection system. One of the most common causes of a lean air-fuel mixture (petrol or LPG) entering an engine is clogged injector nozzles. In this case, one of the possible solutions may be to purge them.
Loading…
