Cycle News - Archive Issues - 1980's

I e o CO 0') :.. ":.- Kawasaki Electronic Fue/.lnjection System (KEFI) Het'e's the lowdown on Kawasa/ci's new fuel injection system which nw.kes its debut on the 1980 ZI000-H. The system wes a mini-computet' (mounted in the tail) to monitor engine revs, throttle setting, engine head and air temperature, fuel and air flow, and start signals. Inlet nw.nifolds are marked 'Mikuni' but we understand that Kawasaki's RIID subsidiary developed the system with some sort of cooperation with the Bosch company of West Gernw.ny. The infornw.tion below was taken from Inside Kawasaki, Kawa.saJci Technical Publications Department offering. The Kawasaki Electronic Fuel Injection (KEFI) System takes the place of conventional carburetors. and provides an electronically controlled fuel! air mixture to the engine. The system operates on the principle of continuous direct air flow measurement to determine the correct fuel/air mixture. SenSors in the KEFI System continually monitor engine speed and temperature, and intake air flow and temperature. This information is sent to the electronic control unit, which processes these signals and determines the fuel requirements of the engine. The control unit then generates an electric signal which is sent to th~ fuel injection valves. The electro·magnetic injection valves open and inject the exact amount of fuel needed in front of the intake valves. The injection valve nozzles are designed to deliver a finely atomized fuel charge, which promotes even and complete com· bustion. Fuel Delivery System The fuel delivery ~tem is shown in the following diagram. The fuel in the tank ~ through the fuel tap to the fuel filter. The fuel pump draws the filtered fuel in, and pumps it into the high pressure fuel line. The fuel is distributed to the four fuel injectors and is injected into each manifold upon receiving a signal from the electronic control unit. The injectors are connected electrically in parallel, and inject fuel all at once. Fuel injection occurs once every 360' of crankshaft rotation, which,means that the injectors inject fuel twice for each cylinder's combustion cycle. In other wor· ds, one fuel injection supplies half of the fuel required for one complete combustion cycle. Fine atomization of the fuel charge is achieved through the design of the injector nozzle. This results in a very homogeneous fuel! air mixture which promotes even burning and more complete combustion. KEFI components The KEFI System consists of the following basic components: - air intake system -fuel delivery system -electronic control system Benefits of KEFI I. Driveability: The KEFI System provides superior cold stan performance with vinually no throttle lag or hesitation. Accelerator pumps are not needed since the signal generated by the air flow meter precedes charging of the cylinders. The fuel/ air mixture is always correct; throttle respons;e is excellent. 2. Better fuel ecGDOIDY: The KEFI System delivers the precise amount of fuel needed over the entire engine speed range. When compared to a normally carburetted engine of the same power output, the KEFI equipped engine delivers better fuel economy. 1 3. Low exhaust emiIIioas: Continuous maintenance of the c.orrect fuell air mixture over the entire engine speed and load range results in low exhaust emissions. Compared to a "arburetted engine designed to meet the same emission levels, an EFI engine can be optimized for better performance, driveability, and fuel economy. 22 4. Low maintenance: The KEFI System automatically takes into account and compensates for all changes occurring during the normal service life of the engine (cylinder/piston wear, combustion chamber deposits, valve clearance changes, etc.). The system always delivers the correct fuel/air mixture. 1. PRESSURE REGULATOR 2. FUEL ALTER 3. FUEL PUMP •. INJECTOR 6. FUEL DISTRIBUTING PIPE 6. VACUUM UNE TO MANIFOLD 7. CHECK VALVE 8. FUEL TAP

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