Shami This makes it run more quietly than a mechanical system does. May Learn how and when to remove this template message. The ECU interprets data from input sensors to, among other tasks, calculate the appropriate amount of fuel to inject. Single-point injection SPI uses a single injector at fule throttle body the same location as was used by carburetors.

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Kirr An electronic system is operated entirely by a microprocessor control unit. One solution is to fit twin-carburettors, but these are difficult to tune correctly.

How does an electric water pump benefit your engine? A high-pressure electric fuel pump mounted near the fuel tank pumps fuel at a pressure of psi up to a fuel accumulator. All this information allows an electronic system to meter the fuel far more accurately than the simple mechanical system, which relies on sensing the airflow injectiom. When signaled by the engine control unit the fuel injector opens and sprays the pressurised fuel into the engine. Unlike carburetor-based systems, where the float chamber provides a reservoir, fuel injected systems depend on an uninterrupted flow of fuel.

The intake is only slightly wet, and typical fuel pressure runs between psi. In fact, most aircraft that use the TCM fuel injection system feature a fuel flow gauge that is actually a pressure gauge calibrated in gallons per hour or pounds per hour of fuel.

Along with this, the engine can operate with stratified lean-burn mixtures, and hence avoid throttling losses at low and part engine load.

W8 W12 W16 W Immediately following the war, hot rodder Stuart Hilborn started to offer mechanical injection for race cars, salt carsand midget racers[9] well-known and easily distinguishable because of their prominent velocity stacks projecting upwards from the engines on which they were used. For the lay individual, the labyrinth of hoses, wire harnesses, manifolds and tubing beneath a car hood might appear intimidating.

All share the central task of supplying fuel to the combustion process, but it is a design decision how a particular system is optimized. Modern systems use a mass airflow sensor to send this information to the engine control unit. Mechanical fuel injection was used in the s and s by many manufacturers on their higher-performance sports cars and sports saloons.

Depending on the system design, the timing of when injector opens is either relative each individual cylinder for a sequential fuel injection SFI systemor injectors for multiple cylinders may be signalled to open at the same time in a batch fire system.

The Factory Lightweight Legacy. By using this site, you agree to the Terms of Use and Privacy Policy. As well as improved control over fuel flow, the electronic system also operates at lower pressure than a mechanical system — usually at around psi.

Porsche continued using this system on its racing cars into the late seventies and early eighties. This residual pressure must be relieved, and if it is done so by external bleed-off, the fuel must be safely contained.

Modern injetion only change the amount of fuel injected to vary output; there is no throttle. Single-point injection SPI uses a single injector at the throttle body the same location as injectin used by carburetors. At precisely timed intervals, intake valves open, corresponding to the different cylinders of the engine.

Most of the 35 vehicles originally so equipped were field-retrofitted with 4-barrel carburetors. Carburetors have the potential to atomize fuel better see Pogue and Allen Caggiano patents. How a fuel injection system works Fuel injection is gradually replacing carburetors in these nations too as they adopt emission regulations conceptually similar to those in force in Europe, Japan, Australia, and North America.

Direct fuel injection costs more than indirect injection systems: The justification for single-point injection was low cost. Most 10 Related.



Once the engine has warmed up to a certain temperature, a thermoswitch automatically cuts off the cold-start injector. In swirl injector, the spray cone angle is controlled by the ratio of the circumferential velocity to the axial velocity and is generally wide compared with nonswirl injectors. The justification for single-point injection was low cost. The primary factor used in determining the amount of fuel required by the engine is the amount by weight of air that is being taken in by the engine for use in combustion.


Aragami Read more essential guides Servicing a mechanical fuel pump Do not clamp a pump in a vi The main difference between electronic injection and mechanical injection is that an electronic system is controlled by a complex microprocessor control unit sometimes called an electronic control unit or ECUwhich is basically a miniature computer. German direct injection petrol engines used injection systems developed by Bosch from their diesel injection systems. Following this racetrack success, the Mercedes-Benz SLthe first production sports car to use fuel injection, used direct injection. Fudl postponed the redesign and tooling costs of these components.


Inside the control unit is another restriction, which controls the fuel mixture. Auxiliary power unit Coffman starter Hydraulic system Ice protection system Recoil start. Fuel injection The fuel is sprayed with the help of a nozzle that is opened and closed with a needle valve, operated with a solenoid. This makes it run more quietly than a mechanical system does.

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