Page 2 of 2 FirstFirst 12
Results 16 to 20 of 20

Thread: Fuel Injectors

  1. #16
    apriliaforum Member Mike Holland's Avatar
    Join Date
    Sep 2012
    Location
    Sydney, Australia
    Posts
    125
    Which part of my post is crap, pray tell?

    When the lambda tells the ECU that the mixture is a bit lean, the ECU says "Good. That's how it should be to meet European emission guidelines." That's why I have the lambda emulator to lie to the ECU about the mixture.

    But according to all my reading, the ECU ignores the Lambda Probe above about 6000 rpm, and just follows its programming according to revs, throttle position, etc, and so I need to override what the ECU is doing in this range and make the mixture a little richer.

    The result should be a tiny bit more power (Maybe quite a lot more, going by what a larger jet did for my GT200), a cooler engine, and a nicer sounding engine judging by my experience with the IWP143 injector.

    Mike
    Last edited by Mike Holland; 02-13-2015 at 06:34 AM.

  2. #17
    apriliaforum expert
    Join Date
    Jun 2013
    Location
    croatia
    Posts
    2,433
    i didnt mean crap to your post

    but crap that you dont have anybody to help you out with reprograming the ecu

    you always can switch the bike from efi to carb and try to tune it

  3. #18
    apriliaforum Member Mike Holland's Avatar
    Join Date
    Sep 2012
    Location
    Sydney, Australia
    Posts
    125
    Sure, there are guys around who tune ECUs for motorcycles, but as far as I know (and I visit all the Australian forums) there are only two other scooterists around who have fitted a V4 cylinder and head, and they are mates of mine. So I am quite certain that there are no ECU tuners in Sydney with experience tuning modified Vespa GTSs. I have already spent a couple of hundred dollars on a Power Commander and a Force Master with no results, and don't want to spend hundreds more getting my scooter set up on a dyno while an ECU expert learns how to tune a modified Vespa.

    I want a cheap option which will cover 75% of the distance to a good setup. Besides, if I find an injector that does the job for me, it will probably do the job for anyone else who wants that bit more without spending hundreds, and can easily do the mod himself with just one spanner.


    Don't want to go back to carbs. I could manage the PHBH30 on my PX210, but never understood the workings of the Keihin CVK30 on my GT200.


    Mike

  4. #19
    Honest always, feared often Micah / AF1 Racing's Avatar
    Join Date
    Jun 2003
    Location
    37 miles E. of ATX, TX USA.
    Posts
    27,886
    My Vespa 300 runs in closed loop for about 95% of its operational time, the only time it appears to rely on open loop operation is in the last 2,000 rpm before the rev limit, and my rev limit is programmed via Rexxer 500 rpm higher than stock, or a true 9,850 rpm. In that last 1,500 rpm I need about 18-20% more fuel to suit my mods, so this setup works perfect with my current injector and fuel pressure. 6,000 rpm is where my motor and tranny meet to start making power under full load with the 11.2 gram rollers and even at WFO in that rpm range fueling is near perfect? Granted my motor and fuel system is radically more modified than most folks it worked very well even using the stock injector with fuel pressure set to 3.5 Bar and stock ecu calibration/mapping.
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  5. #20
    apriliaforum Member Mike Holland's Avatar
    Join Date
    Sep 2012
    Location
    Sydney, Australia
    Posts
    125
    OK, so you've got standard injector and increased fuel pressure. I am trying a larger injector and standard fuel pressure. Either way should work the same to increase fuel delivery. Just have to get the right size injector for my setup.

    My assumption that the Lambda probe is only effective up to about 6000 rpm is based on what I read on the forums. If, as you have found, it is active up to 95% of the rev range, then presumably over this range the ECU will try to undo any changes I make, and without reprogramming the ECU I am wasting my time. Bugger. I wish that Force Master had worked. But at least the Lambda Emulator should then be making a difference over that 95% of the range.

    According to my service manual, the Lambda probe is an all-or-nothing affair - signals oxygen present or oxygen absent, and nothing in between. So how then does the Lambda emulator or the Fat Duc work by attenuating the signal?

    Mike

Page 2 of 2 FirstFirst 12

Similar Threads

  1. Stp Fuel Injector Cleaner
    By steve799 in forum Scarabeo 50 Ditech, SR 50 Ditech, SR Factory
    Replies: 11
    Last Post: 08-02-2006, 10:23 AM
  2. Clogged fuel injector?
    By lgcivttu in forum Scarabeo 50 Ditech, SR 50 Ditech, SR Factory
    Replies: 0
    Last Post: 02-13-2006, 10:35 PM
  3. fuel injector
    By atomicjake in forum Scarabeo 50 Ditech, SR 50 Ditech, SR Factory
    Replies: 2
    Last Post: 10-27-2005, 07:12 AM
  4. Polini 70cc kit owners - re: fuel injector
    By justo316 in forum Scarabeo 50 Ditech, SR 50 Ditech, SR Factory
    Replies: 15
    Last Post: 11-01-2004, 09:22 AM
  5. Fuel Injector cost
    By mariolebbe in forum RSV1000 Mille, Mille R, and Mille SP (1998-2003)
    Replies: 0
    Last Post: 08-18-2003, 03:40 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •