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Old 06-20-2013, 07:57 PM
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puppypaws puppypaws is offline
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Join Date: Jul 2004
Location: Marshville,NC 28103
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Originally Posted by greenology View Post
Even though the system is running in open loop on start up, its running on a pre-programmed map for a cold engine, ie replaces the choke. Also as GMLC suggests, the EFI system is much better than a carb/choke system working on venturi, the fuel pressure is primed and ready before the starter motor turns, unlike a carb engine which would need to draw the fuel/air mix in.

I really wish we had more EFI options available over here atm.
I would say the statement above is a big part of why they crank so easily, but I'm wondering what the difference would be (no big deal) in why his acts a little sluggish to begin with? I can walk outside to my mower (has not been started today), turn the ignition switch and the engine will immediately start, can leave it at 1/3 throttle and drive off with the engine acting as if it had been running for an hour.

I am really interested in how the injected BB acts in comparison, and TLS is the perfect one to give this answer.

Comparison between open and closed loop:

The Kawasaki system is an "OPEN LOOP”, non-feedback
System. This means that it follows a predetermined fuel map with no
feedback or ability to adapt to changing conditions or altitude. The
Kohler EFI is a Delphi designed "CLOSED LOOP " feedback fuel injection
system. This system uses an oxygen sensor and various inputs (from the
speed sensor, oil temp. sensor and throttle position sensor) to
determine what fuel and ignition requirements needed to constantly adapt
and deliver maximum efficiency. While actual testing in the Lab has
shown a fuel efficiency gain of only about 10 to 12 percent at WOT and
full load, field-testing has shown gains in the neighborhood of 30
percent due to the various speed and load requirements.

The open loop fuel injection systems improved cylinder-to-cylinder fuel distribution and engine operation over a wide temperature range, but did not offer sufficient fuel/air mixture control to enable effective exhaust catalysis. Closed loop fuel injection systems improved the air/fuel mixture control with an exhaust gas oxygen sensor. The O2 sensor is mounted in the exhaust system and enables the engine management computer to determine and adjust the air/fuel ratio precisely and quickly.
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