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Delphi's Ion Sense Ignition Subsystem 'Sparks' Interest

    FLINT, Mich., April 18 In the past, a spark was all it
took to initiate combustion in an engine.
    These days, to meet tougher emission standards, achieve improved fuel
economy and reach optimum vehicle performance, ignition subsystems need to be
much more sophisticated and precise.

    Delphi Automotive Systems , a world leader in fuel handling and
ignition systems technology, has been working with Isuzu Motors to supply ion
sense ignition subsystems for model year 2000 and beyond, Rodeos and Troopers.

    The ion sense ignition subsystem consists of one ignition coil per
cylinder together with a high-temperature, vibration-resistant engine mounted
electronic module, utilizing hybrid circuit board technology.  The system has
no moving parts or high voltage leads, which assures maximum energy supplied
to the spark plug.  The spark plug is used as an actuator to ignite the
air/fuel mixture, then as a sensor to monitor the combustion process.  Once
the spark is over, a DC voltage is applied which biases the spark plug gap.
If ions or free electrons are present in the gap, current will flow in the gap
-- the current is then measured by the system.

    "This supply agreement is another example of how Delphi's unique approach
to systems development is becoming more attractive to our customers," said R.
Scott Bailey, director of engineering, Delphi Energy & Chassis Systems.  "By
working with our customer, in this case Isuzu, early in the design stage, we
were able to develop entirely new ignition subsystem technology and components
that not only meet critical performance expectations, but provide greater
value and new functionality."

    There are three primary benefits of Delphi's ion sense ignition subsystem.
By utilizing an individual direct in-cylinder measurement of combustion,
misfire detection is possible over virtually the entire engine speed and load
range, and knock detection is improved through individual cylinder sensing.
System cost is reduced through the elimination of knock, camshaft position and
rough road sensors.

    "Today, Delphi's ion sense ignition subsystems provide great misfire and
knock detection and the systems will be the foundation for future technology
enhancements," explained Phil Peterson, Delphi's technical project manager for
the ion sense system.  "By extracting further information from the signal,
other advanced functions such as air/fuel ratio detection will be possible.

    "Delphi's successful implementation of these functions to an inductive
ignition system is an industry first," said Peterson.  "The robustness of the
Delphi system has now been proven in a successful first year of production."

    The system was developed globally through the coordinated efforts of Isuzu
Motors and Delphi's technical centers in Brighton, Mich., Anderson and Kokomo,
Ind., Tokyo, Japan and Bascharage, Luxembourg.  The ignition coil is produced
at Delphi's Seixal, Portugal plant.  The ion sense ignition module is produced
at Delphi's plant in Singapore.