Discussion in 'Lawn Mowing Equipment' started by GMLC, May 4, 2013.

  1. greenology

    greenology LawnSite Senior Member
    Messages: 816

    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.
  2. puppypaws

    puppypaws LawnSite Fanatic
    Messages: 9,177

    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.
  3. greenology

    greenology LawnSite Senior Member
    Messages: 816

    Whats TLS using, save me looking through his posts.
  4. greenology

    greenology LawnSite Senior Member
    Messages: 816

    I know its the Lazer wit RED etc, but im confused from your post whether you saying he has EFI with a continuous open loop?
  5. Ridin' Green

    Ridin' Green LawnSite Fanatic
    Male, from Michigan
    Messages: 17,820

    He has the new BB Kohler EFI closed loop system on his RED mower.
  6. TLS

    TLS LawnSite Fanatic
    Messages: 7,943

    My ears have been ringing all afternoon!!! Now I know why!

    I've only had the 28EFI on my SuperZ and now the 34 EFI RED on the new Lazer. Both are night and day different in power, yet very similar in a lot of ways.

    I had my idle set at 1200 on the SuperZ, so initial startup at low idle wasn't like it should have been. It was great at 1800 or so though. By the time I got it off the trailer, I could engage the blades at idle.

    The only thing I notice with the new engine is that it'll take about one more cranking revolution before it fires. Nothing wrong...just probably a crank trigger system vs whatever the old one used.

    PSC has the new 29 which has a lot of newer features. Everything is engine mounted: pump, filter, ECM, etc. where Puppy and I had all separate components.
    Posted via Mobile Device
  7. puppypaws

    puppypaws LawnSite Fanatic
    Messages: 9,177

    I'm trying to understand what may cause this sluggish feeling for the short time he speaks of, have you felt this any whatsoever in your new engine? I know my efi's always felt like they were pre-warmed the instant they start, never felt the slightest flutter of any type, even at 30°. I've honestly always been astonished at how well they do operate, and in every aspect.
  8. TLS

    TLS LawnSite Fanatic
    Messages: 7,943

    Puppy, what are your idle RPM's? Mine were cranked way high from the factory IIRC. Maybe yours is still set high?

    Plus, his is brand new!
    Posted via Mobile Device
  9. greenology

    greenology LawnSite Senior Member
    Messages: 816

    Is this what you are referring to Puppy?

    Hmm if I was to take a guess, which is all it is, Id say its running rich (which is not necessarily wrong) for a longer period of time, being rich could be a reason for it to chug a little while given any load.
  10. puppypaws

    puppypaws LawnSite Fanatic
    Messages: 9,177

    I've always checked my high end, never been concerned with the low end, but I can tell the new engine is higher on the idle end than the old engine was. The old engine would get down and purr like a kitten, so low I honestly thought it to be impossible to engage the blades in idle position without stalling the engine, but she would start them spinning with what seemed to be no effort, or change in sound.

    I am going to check mine today for curiosity, but already know they are set several hundred higher than the old engine.

    This is the standard below:

    Adjustment Procedure

    1. Make sure there are no fault codes present in the
    ECU memory.

    2. Start the engine and allow it to fully warm up
    and establish closed looped operation
    (approximately 5-10 min.).

    3. Place the throttle control in the ‘‘idle/slow’’
    position and check the idle speed with a
    tachometer. Turn the idle speed screw in or out as
    required to obtain 1500 RPM, or the idle speed
    specified by the equipment manufacturer.

    4. The low idle speed adjustment can affect the high
    speed setting. Move the throttle control to the full
    throttle position and check the high speed. Adjust
    as necessary to 3750 RPM (no load), or the speed
    specified by the equipment manufacturer.

Share This Page