Fuel-Injection technology explained


What is a Fuel-Injector?


Fuel Systems Explained – Fuel-Injection

A fuel-injector is a device controlled by the ECU (Electronic Control unit) that delivers the correct air-fuel mixture to the combustion chamber. A number of sensors monitor parameters like combustion chamber temperature, oxygen content, exhaust gas temperature etc. Based on inputs from there sensors, the injector delivers the necessary air-fuel mixture to the combustion chamber by using pre-set maps stored in the ECU. The use of a pressure pumps allows for high injection pressures which in turn result in more complete combustion, thereby reducing emissions.

What are the advantages?

The fuel-injector, with new developments in technology, is very accurate. It can precisely vary the amount of fuel and air entering the combustion chamber according to different requirements like idling, acceleration, cruising etc., based on throttle input. As a result the quality of combustion is much better resulting in fewer harmful emissions. When it is combined with a catalytic converter, the emissions are reduced by a large margin. The use of fuel-injector also results in better atomisation and smoother ride.

What are the limitations?

The fuel-injector required the use of sophisticated sensors and pressure pumps which usually shot up cost of production. Also, it was cheaper to adjust the carburetor than to change fuel maps on the ECU (for injectors). To say that the fuel-injected bikes develop more horsepower is also not true as some of the powerful bikes in history were carbureted. Replacing a damaged injector component was is also expensive.

Scope for the future

So, is the Carburetor becoming irrelevant as every minute passes? Certainly not, especially in a volume focussed market like India where majority of bikes are sold only because they are affordable and cheap to run. Manufacturers in India just cannot accommodate for the high cost of the fuel-injectors. Hopefully, in the future, more stringent emission norms will force manufacturers to switch to an injector. Major manufacturers like Hero Motocorp, Yamaha and Bajaj have started to introduce fuel-injected bikes recently, which is a good sign. Even the iconic Royal Enfield has joined the fray by using fuel-injection on the Continental GT. However, in the short term, new bikes, especially in the commuter segment will continue to be equipped with carburetors.