Excessive chamber deposits disrupt ideal combustion and performance by absorbing fuel and by disrupting proper air flow within the cylinder. Typically these deposits can build upward in the piston bowl area. This changes the air flow within the chamber away from the ideal movement designed when the powerplant was engineered, and this leads the engine away from idea combustion. Taking in fuel happens because step deposits are porous with a network of splits and crevices that can work as sponges.
All diesel engines use some form of fuel injection. Many small diesel engines used to use a system called indirect injection (ID1) while larger engines use direct injection (DI). These days, most modern passenger car diesels have switched to DI for fuel economy reasons. IDI tends to be smoother and less busy, while DI is more fuel efficient. The fuel injector sprays the diesel-powered fuel into hot, pressurized air, and the combination auto-ignites. Efficient metering, atomization and fuel-air mixing are key requirements for good combustion and particularly important for low levels of wear out emissions.
Both gasoline and diesel Fuel Level Sensors consist of components that boil over a wide temperature range (the diesel range is higher than the gasoline range). When the powerplant is switched off, gas remaining in or close to the pintle tips mixes together with any remnants of un-burnt engine oil and is subjected to high heat soak temperatures. This kind of high temperatures lead to the formation of free radical species, and then to a combo of auto-oxidation, chemical rearrangement and degradation of the staying fuel – and build up form within the injector.
Clean fuel injectors are critical for efficient diesel engine operation. A highly dispersed spray pattern maximizes fuel-air mixing, while good atomization ensures rapid, efficient combustable. All diesel fuels, but especially those containing products from refinery conversion procedures, have a tendency form a little level of coke in the annulus of the injector. This coke is believed to be caused by the thermal decomposition of unstable compounds in the fuel. It is such a common problem that injectors are designed to tolerate a certain level of coke. On the other hand, lots of today’s diesel powers give excessive levels of injector coking, disrupting the fuel spray pattern and degrading atomization.
Higher emissions, noisier engines and a decrease in fuel economy are the result, as shown by manipulated vehicle studies. These studies show upwards to a 15% reduce in city economy and 5% decrease in road (according to EPA test protocols). For the FTP driving protocol, the results are a 2-11% reduction in fuel economy over the FTP driving protocol, depending on degree of plugging (8-30%).
Typically the biggest effect from these deposits comes when they get adequate to physically block the manifold passage and prohibit air and fuel movement into the cylinder. This was previously quite common when carburetors were widespread, and would cause poor speeding, power, gas efficiency and brought up emissions. But even low levels of deposit accumulation can affect mileage and emissions, since the downpayment can act as a sponge, absorbing fuel into the pores of the deposit, then releasing the fuel through evaporation or desorbtion (release of absorbed fuel). This disrupts the flow of fuel at the proper timing time period into the cylinder and reduces droplet evaporation efficiency, thus creating an disproportion in the fuel/air mixture into the cylinder. And this means the engine is not functioning or combusting fuel optimally.