Fuel injection is of two types and ECU's are of two types.
First closed loop, in short open loop is similar to carbs.How in carbs there are jets(pilot,main) and when the throttle is pulled the carb sucks the fuel and and mixes and injects it into the engine.In normal carb fuel is decided according to the position of throttle.In open loop FI instead of carbsucking and creating pressure the fuel pump creates pressure and the injectors inject the fuel done by jets in carbs.In open loop the ECU is given throttle and rpm input according to which it decides the amount of fuel which is predetermined and does not change in different atmospheres.The fuel entering the engine atomizes and mixes with the air better,hence a better combustion resulting in better fuel economy and throttle response.
On the other hand in closed loop system there is a formula whose values are determined by various sensors, and one of the most important being Lamba(O2) sensor and engine temperature.Hence these are better in terms of performance and fuel economy bacause they work real time calculating the amount of fuel rather than looking up in the table and responding.But because of complexity of the ECU and more number of sensors the cost of these closed loop system is more.The best way to find out if the FI is closed or open loop is to examine the entire exhaust pipe from the engine all the way to the end can.I think all the Hero Honda bikes(and Honda) FI bikes have closed loop system.
Even in closed loop systems there are two types of injection,Direct injection and throttle body injection./in throttle body injection the fuel is injected in throttle body which mixes with air and then is sent to the engine.
In direct injection there is another sensor ie. crank position sensor, this sensor help the ECU to know when the valve will open and hence the fuel and air is directly injected into the engine rather than throttle body.Hence this results into even better fuel economy and throttle response(but this throttle response is better felt in the midrange.
But u cant tell from the outside(without removing some body parts) easily that whether the bike is TBI or direct injection




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