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Research involving the use of natural gas in internal combustion engines has been intensified due to concerns with the environment and exhaustion of fossil fuels reserves. In Brazil the abundance of natural gas, together with the need to reduce green house gases emissions and noise of urban buses, presented the opportunity to develop a Diesel-CNG control for Diesel engines using a mechanical diesel pump. An add-on system was developed using a production Engine Control Module. In this system, compressed natural gas (CNG) is added into the intake air stream and a pilot injection of diesel fuel is used to achieve ignition. One advantage of the Diesel-CNG system over a diesel engine converted to CNG usage using spark ignition is that the engine can operate in a diesel only mode; not reducing the resale price of the vehicle to regions less served with CNG fueling stations.

Research involving the use of natural gas in internal combustion engines has been intensified due to concerns with the environment and exhaustion of fossil fuels reserves. In Brazil the abundance of natural gas, together with the need to reduce green house gases emissions and noise of urban busses, presented the opportunity to develop a Diesel-CNG control for Diesel engines using a mechanical diesel pump. An add-on system was developed using a production Engine Control Module. In this system, compressed natural gas (CNG) is added into the intake air stream and a pilot injection of diesel is used to achieve ignition. One advantage of the Diesel-CNG system over a diesel engine converted to CNG usage using spark ignition is that the engine can operate in a diesel only mode; not reducing the resale price of the vehicle to regions less served with CNG fueling stations.

The injector was developed to operate in multi-point, port fuel injection system for multi-fuel vehicles. It is controlled by the same Engine Control Module of the vehicle, with no need of additional controllers/emulators, allowing total integration with vehicle's system. All control features and resources are permanently active, ensuring the best performance in emissions, drivability and diagnostics, independently of the fuel being used. This paper describes the functional requirements for this component, the development stages, the resources used in each stage, and results obtained in functional performance of injectors and the system effects in regards to exhaust emissions and engine performance.

Ethanol has been used in Brazil as a passenger vehicle fuel since 1979. Until the year 2000, vehicles were made to run exclusively with either gasoline or ethanol. The MultiFuel® engine control module (ECM) was developed allowing vehicles to use fuels with any ethanol percentage, relying only on the existing oxygen sensor as opposed to an add-on ethanol sensor for the percent ethanol evaluation. The use of tank fuel level information allowed for far more robust ethanol percent detection and improved driveability. Four years later, compressed natural gas (CNG) capability was integrated into the MultiFuel® technology. Prior to that, vehicles using CNG normally required a second ECM; however, the performance wasn't always optimal. The MultiFuel® integrated with CNG capability is known as the Tri-Fuel system. It uses only one ECM, seamlessly controlling both liquid (ethanol blends and gasoline) and CNG fuels with little power loss, and excellent driveability and fuel consumption.

Brazil launched the Ethanol vehicle program in 1979. The production raised to more than 80% and declined to low values due to Ethanol shortage problems. In 2000 E100 usage was fostered again and Delphi developed the Multifuel® System where the vehicle could use fuels with any ethanol percentage. The production of Multifuel vehicles reached 35% and is increasing. Besides that Brazil is experiencing an abundance of CNG. CNG converted vehicles normally use a second ECM, however the performance isn't optimal. In 2004 Delphi developed a MultiFuel-CNG system with one ECM controlling both fuels with little power loss and excellent driveability and fuel consumption.