Engine Management Essay

Engine Management System ensure that engines run cleanly and efficiently in a wide variety of conditions, they are for the most part reliable and require little or no maintenance. Two basic functions performed by an EMS: (1) to meter fuel to the engine in the right quantity and (2) to provide a spark at the right time. An EMS is a self contained custom built computer which controls the running of an engine by monitoring the engine speed, load and temperature and providing the ignition spark at the right time for the prevailing conditions and metering the fuel to the engine in the exact quantity required. There are two discrete subsystems in operation within the EMS The fuel or injection system and The ignition system. When the engine is running its requirements for fuel and ignition timing will vary according to certain engine conditions, the main two being engine speed and engine load. This Map injection gives the appropriate fuel or timing setting for each possible speed and load condition. There will normally be a map for the injector timings (fuel map) and a separate map for the ignition timing settings (ignition map) within the EMS. Each map has entries for a pre-determined range of engine speeds (called speed sites) and a predetermined range of engine load conditions (called load sites), which generally indicate how far open the throttle is. The EMS knows the engine speed (derived from the crank sensor or distributor pickup) and the engine load (from the Throttle Position Sensor or airflow meter) and will use these two values to ‘look-up’ the appropriate fuel and timing settings in each map. If the current engine telemetry falls between the sites in the map then the value is interpolated between the nearest two sites. Normally there will be speed sites every 500 or so RPM and 8 to 16 load sites between closed and open throttle. In the example below speed sites are spaced every 1000-RPM and the eight load sites are numbered 0 to 7. An all-new line of V6 engines, with more horsepower, powers the 2006 Mercedes-Benz C-Class and more advanced technology than before. The luxury models feature a high-tech seven-speed automatic transmission, and the C350 Luxury sedan has the classic Mercedes balance of ride quality and handling. The line also includes sport models for those who want a sportier driving experience. Inside, the C-Class cars look and feel like a Mercedes-Benz, with firm, supportive seats and mostly high-quality materials. The C-Class delivers Mercedes engineering and safety technology, with optional all-wheel-drive that will improve traction in wet or wintry conditions. New engines for 2006 complement the substantial C-Class updates made just a year ago.   Mercedes redesigned the C-Class interior for 2005, freshened the exterior styling and further distinguished the sport models from the standard luxury sedans. A new six-speed manual transmission greatly improved shift action. New paint technology imbeds microscopic ceramic flakes in the clear coat finish, increasing its resistance to chipping and degradation over time. Aerodynamically, the C-Class cars are among the most efficient in the Mercedes-Benz family. The C-Class boasts a drag coefficient of 0.27, which helps minimize wind noise and improves fuel efficiency.   Interior Features The C-Class interior looks like the inside of a Mercedes-Benz should, and for the most part, it feels that way, too. A model re-alignment for 2006 has increased the level of luxury in the least expensive models. Fabric upholstery and manually operated seats can no longer be found in the C-Class line. The C-Class got a thorough interior re-do for the 2005 model year so the 2006 models benefit from that. The dashboard, instruments and seats were redesigned, and materials were revised throughout. The instrument cluster now features four gauges, with a chromed-ringed tachometer and speedometer of identical size sitting front and center. To the left and right of these are smaller fuel and temperature gauges. In the middle sits an LCD display with various system and trip functions. Fashioned in the mold of the larger Mercedes E-Class, the instrument cluster is deeply hooded and virtually eliminates glare on the dials. The backlit script is clear and easy to read. Audio controls are now located in what we consider the optimal spot: above the climate control switches, which sit at the bottom of the stack. Both audio and climate knobs are large and easy to locate. The switchgear is, for the most part, easy to use and understand. The stalk controls have a beefy feel with positive detents. Redundant buttons on the steering wheel let the driver operate the audio and telephone functions without removing a hand from the wheel. Lighting inside is effective, with good illumination for entry in the dark and excellent map lights for reading. The C-Class glove box is a good size, unless you order the CD changer, in which case you lose most of its storage space. In general, the C-Class sedans are trimmed with good-quality interior materials. Driving Impressions The 2006 Mercedes-Benz C-Class sedans have been improved across the board, thanks to a new family of V6 engines. The least powerful of the new C-Class engines, the 2.5-liter V6 in the C230 Sport sedan, rated at 201 horsepower, offers more power than the supercharged four-cylinder engine it replaces. As important, it is far smoother at all speeds and generally, fewer courses in feel, sound or the amount of vibration it generates. The 228-hp 3.0-liter V6 in the C280 Luxury sedan is much more powerful and satisfying than the anemic 2.6-liter V6 in the 2005 C240 (previously the best selling C-Class). Even the biggest V6, which was our favorite engine on the 2005 models, is much better for 2006. The 3.5-liter V6 in the C350 generates 268 horsepower, 20 percent more than the 3.2 in the 2005 C320, which improves acceleration performance considerably. Matched with either the six-speed manual or the high-tech seven-speed automatic, the new engine makes the C350 more responsive than the 2005 C320. The 3.5-liter V6 has fully variable valve timing to deliver an impressive amount of torque from idle all the way to the red line. The C350 responds more immediately than the C320, no matter how fast it is already traveling when the driver presses the accelerator. The new engine is also noticeably smoother, particularly at high rpm. In addition, thanks the seven-speed automatic, the improved performance comes without a corresponding decrease in fuel mileage. All of the C-Class cars offer nice steering, effective brakes and a good balance between ride and handling. Before choosing between a Luxury or Sport model, C-Class buyers should carefully consider whether a smooth ride or sharper handling is preferred because the trade-off between comfort and response changes with the model. The Sport models are more firmly sprung than the standard Luxury models. All C-Class models are quiet inside, even when blasting along at 80 mph. These sedans are aerodynamically slippery cars, and very little wind noise penetrates the cabin. As mentioned, the C-Class offers a choice of transmissions. The seven-speed automatic that comes on the C280 and C350 Luxury sedans is superior to five-speed automatics that come on most cars (to say nothing of an old-fashioned four-speed automatic). With more gears, it offers better acceleration performance and responsiveness around town as well as enhanced fuel efficiency. Gear changes are barely noticeable in normal driving, especially in the higher gears. This transmission allows significantly quicker acceleration for highway passing situations, and it does not have to go through every gear. Step on the gas and the transmission will skip down to the appropriate gear, switching from seventh to fifth, for example, and from there directly to third, meaning two downshifts instead of four. As for the manual transmission, Mercedes has lowered the ratio for first gear for quicker acceleration off the line, but kept an overdrive sixth gear for quiet, low-rev highway cruising and better fuel economy. More important, the old cable-operated shift mechanism has been replaced by a solid, direct rod. The result is easier, quicker and more precise shifting, and the improved action contributes greatly to a more rewarding, engaging driving experience. Shift effort is low, and the gears are easier to hit. For manual fans, we can heartily recommend the C230 Sport sedan. If you prefer an automatic but want a Sport model, we encourage you to step up to the C350 Sport sedan with the optional automatic. The optional 4MATIC all-wheel-drive system delivers power to all four wheels. It is fully automatic and on all the time, so there are no buttons to push and no special knowledge is needed; just drive the car. The system uses electronic traction control to vary torque each of the four wheels, diverting power to the tires with the best grip. Even if three wheels lose traction, 4MATIC can direct power to the one remaining tire with grip. The result is better stability and improved handling in slippery conditions, with a greatly reduced chance of being stuck. 4MATIC does dampen engine response and slow acceleration slightly, and lowers fuel mileage a bit. However, for those who drive through harsh winters, all-wheel drive is worth it. All-wheel-drive sedans such as the C-Class are proof that you do not need an SUV to confidently handle rough weather. In fact, a car tends to handle better in icy conditions than a truck. We consider all-wheel drive a valuable asset in the rainy Northwest or for the harsh winters of the Midwest and Northeast, and 4MATIC is priced much lower on the C-Class models than it is on other Mercedes models. Braking is excellent. Every C-Class model has good-sized brake rotors, and the Sport sedans feature cross-drilled rotors in front for better resistance to fade. (Braking effectiveness fades away as brakes get hot from repeated hard use.) All C-Class cars come with Electronic Brake-force Distribution (EBD) and Brake Assist. EBD can reduce stopping distances and improve stability when braking by distributing brake pressure between the front and rear wheels, giving more to the tires that are gripping best. Break Assist senses a panic-braking situation and helps ensure full braking force even if the driver makes the mistake of relaxing pressure on the brake pedal. The net effect is short, no-fuss stopping. In everyday use, the C-Class brakes are progressive in pedal feel. The C55 AMG might be the most impressive C-Class yet. It is a sports sedan in the extreme sense, capable of amazing acceleration, and handling and braking on par with exotic sports cars. It is capable of accelerating from 0 to 60 mph in an exotic-grade 4.9 seconds, according to Mercedes. The old C32 was super quick, too, but the C55 is less crude and more refined. Its big V8 engine is smoother, more tractable and less intrusive when a driver is cruising the freeway or just trundling along, and its deep, V8 exhaust note better suits the sportiest C-Class of all. How to maintain the engine of a car If we will take one look, why cars break down? We can see several things. Sometimes cars start having problems after accidents. Sometimes it may be a factory defect or design flaw. Heavy conditions like, for example, driving only short trips without letting the engine to warm up fully also make the engine life shorter. Corrosion is another factor – for example, park the car for a few months in place with high humidity and later it will probably have more problems than the vehicle driven all this time on daily basis.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   One of the most reasons for a car to break down is maintenance. There are important remainders to maintain the car in good shape. A regular oil change may keep engine running, avoid overheating the engine, changing spark plug, air filter, timing belt and other items from maintenance schedule may save from money. Fixing a small problem will avoid a serious damage in your car. Engine Oil Change Regular oil change is very important in maintaining a car. Engine oil has limited life – after a certain point, it starts losing lubricating qualities and carbonizes. Once it happens, the engine is contaminated with carbon deposits or sludge that significantly shorten engine’s life. When you change oil at or before manufacturer suggested interval, you change the oil before this â€Å"carbonizing† point, engine remains clean and once refilled with new oil ready to work hard again. If the engine oil has not been changed for long, carbon deposits start clogging the oil pick-up screen decreasing oil supply and increasing friction. Through the engine ventilation system the same carbon, deposits build up inside the throttle body and EGR system causing rough idle and possible check engine light. Compression decreases and engine start wearing much faster. If you do not remember when you changed the oil in your car last time – just check the oil on the dipstick. Moreover, every time you change the oil, the oil filter should be replaced as well. For correct oil type, engine oil capacity, maintenance schedule, etc. check your car owner’s manual or find car technical information. B.  Ã‚  Ã‚  Ã‚   Checking the engine oil Check the engine oil at least once a month or even more if the car has a mileage. Driving with extremely low oil level (less than min.) or with low oil pressure warning lamp on may cause serious engine damage. Have your engine be inspected as soon as possible if the oil pressure gauge indicates extremely low oil pressure. Always use the appropriate engine oil type. Change the oil if you notice that the color is black. Check your parking space for leaks. If you find any, fix it before it results in more serious vehicle problem Concerning the type of oil that you will use there are a comparison with synthetic oil and conventional mineral oil. The advantage of synthetic oil is that it can withstand higher temperature and can work longer without losing its lubricating qualities. It does not get thicker at below-zero temperatures providing good engine lubrication at a cold start. However, since it is more â€Å"thinner† a high-mileage engine filled with synthetic oil will more likely to develop leaks and you will more likely to hear lifters tapping noise at a start. Therefore, If you have low mileage or turbo engine and driving under heavy conditions such as high temperature, excessive load, long intervals without an oil change, etc., or simply want to provide extra protection for your engine, synthetic oil may be a good solution. Nevertheless, I do not think it is worth to use synthetic oil in high-mileage engines – thicker mineral oil will provide better protection as long as you change it regularly. C.  Ã‚  Ã‚  Ã‚   Engine cooling system Engine overheating causes serious engine damage. In order to avoid the engine overheating: Check the coolant level periodically. It should be at least at the â€Å"min† mark in the coolant reservoir. If it is lower, add the coolant bringing the level to the â€Å"max† mark. Avoid coolant leak it may cause an engine overheating. The engine temperature start rising higher than the normal, have your engine inspected. Check the front of the radiator – sometimes it may be obstructed with leaves or dust. It is one of the possible reasons for the overheating. Never open the radiator or the coolant overflow reservoir when engine is hot! Tune –up, Timing Belt, Fuel Injector flush There are certain vehicle components that need periodical replacement such as: The fuel filter-dirty fuel filter may cause engine stalling and loss of engine power. Air filter –dirty air filter causes loss of engine power, increased fuel consumption, airflow sensor failure, etc. Engine coolant – old engine coolant loses its anti-corrosive and other characteristics and may cause water pump to fail. Spark plugs – simply spark plugs replacement can significantly improve the engine performance. Timing belt – timing belt failure may cause serious engine damage, especially if it’s diesel engine. Battery The battery filled with harmful acid solution and can produce explosive gases. Handling a battery be careful and always use protective glasses and gloves. Do not use open fire, smoke, or create a spark near battery. Most of batteries nowadays are maintenance free. All you check is battery terminals that should not be loose or corroded. Corroded battery terminals will cause all kind of problem: blinking instrument lights, low charge, no-start, dim headlights, check engine and ABS malfunction light etc. If you see any acid leaks, cracks or any other damage – replace the battery. Acid leaking from the battery destroys everything underneath. If there is any problems with your engine, such as irregular noise or smell, or performance problems, leaks or smoke, or â€Å"check engine† light is on, etc., have your car inspected with a mechanic. It is always better to fix any small problem right away before they can cause engine damage. Be aware, some mechanics will try to scare you because they always want to sell you more job than your car really needs, so always ask to explain everything, to show you what exactly is wrong and why. For vehicles with turbocharger, the Turbocharger serves to pump more air into the engine boosting engine power without increasing the engine volume. This turbo charger works at a very high temperature that why it requires a quality engine oil. Low quality, or old contaminated oil can be easily cooked under high temperature in the turbocharger causing it to fail. Here are some considerations: 1.  Ã‚  Ã‚  Ã‚  Ã‚   If it is not against manufacturer recommendations, use synthetic oil, or at least be very accurate with regular oil changes. 2.  Ã‚  Ã‚  Ã‚  Ã‚   When you stop the car after hard driving (speeding, accelerating, etc.) do not shut the engine off right away, let it idle for a while to cool down the turbocharger. 3.  Ã‚  Ã‚  Ã‚  Ã‚   Very long uphill driving under constant load may also cause turbo to overheat, try to avoid it if possible. There are few tips on how to improve the emission test result. 1.  Ã‚  Ã‚  Ã‚  Ã‚   Change oil before testing. For old or high mileage car using thicker oil may help. 2.  Ã‚  Ã‚  Ã‚  Ã‚   Change spark plugs and air filter if it was a while ago since you have changed them last time. Complete tune-up may be an option for older cars. 3.  Ã‚  Ã‚  Ã‚  Ã‚   Flushing the fuel injectors usually help. Before conducting the test you must check and adjust the tire pressure, fill the car with premium gas. Take a car for a spin on a freeway – it helps to clean spark plugs and catalytic converter and make sure, the engine is fully warmed up before test. If you have check engine light on, exhaust leaks, broken gas cap, or any other problem with vehicle emission system it needs to be repaired before the test – all those items will be inspected during the emission test. Reference: Samarins.com ;Illustrated guide to car buyers and owners. (2006)â€Å"Few tips on engine maintenance† http://www.samarins.com/maintenance/engmain.html Aol.com (2006); â€Å"Engine Management†. http://members.aol.com/dvandrews/ems.htm#topics Auto Mall USA (2006) â€Å" Mercedes Benz C-Class† http://www.automallusa.net/1996/mercedes-benz/e-class/reviews.html Horst Bauer   (2004)â€Å"Diesel Engine Management† Robert Bosch GmbH p.9 Horst Bauer (2004)â€Å"Gasoline Engine Management† Robert Bosch GmbH p.9 Hutchinson Education. (2004) †Fundamentals of Automotive Electronics â€Å" V. A. W. Hillier 1987,1996