Fuel injection has been traditionally used in cars for a very long time now, but in the past decade it has been implemented successfully in bikes as well. But in markets like China, there was a huge demand to apply this system to the sub 150cc bikes, which is, by sales the largest market in the country.
Global automotive equipment supplier Denso has stepped up to this challenge and developed a new system, called the DIET-Fi (Denso Intelligent Economical Technology – Fuel Injection). This technology has the same environmental performance and fuel economy as the standard fuel injection technologies, but with a few changes. The DIET-FI does not use a throttle position sensor or an engine temperature sensor, which reduces the overall cost.
The cost has been further reduced by eliminating the ISC idle speed control step motor and the intake air temperature sensor. All of this has been replaced with a temperature estimation control system which uses a thermistor integrated to a control unit. The fuel flow control uses an air intake pipe pressure sensor to gauge the acceleration or deceleration.
Denso has always been developing new systems to reduce environmental effects of cars and motorcycles by improving their economy and reduce the harmful CO, CO2 and other emissions. Denso is also at the forefront for developing products for a specific market which cannot or is not implemented elsewhere.
DIET-FI is manufactured by a Denso group company, Gongcheng DENSO (Chongqing) Co. The company manufactures various motorcycle components and has started supplying the DIET-FI to Wuyang-Honda Motors (Guangzhou) Co., Ltd.
How FI systems for Motorcycles work:
The building blocks for these systems are ECUs, sensors and actuators, which enable very high control of the air-to-fuel ratio. The fuel flow rate or fuel volume is calculated based on engine condition, air volume etc. Injectors feed the fuel to engine from the fuel pump with very high precision.