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sportsman efi/noise?

Discussion in 'FAST Support Forum' started by J.K., Aug 2, 2019.

  1. J.K.

    J.K. Member

    Joined:
    Aug 7, 2016
    Hey guys,

    I've been having some weird tuning issues with my sportsman. So looking over logs I started noticing what looked like possible electrical noise. Im already running resistor plugs, Magnecore plug wires, all wiring is far away from existing high voltage wires. First thing I noticed was on my TPS % dash it was always reading 004% at idle no matter how many times I calibrated it. As a test I temporarily grounded the ECU to the body and presto!! my idle TPS % reads 000 at idle every time, and ramps up normally. So I went further with the testing as I was also seeing AE fuel adding when I felt there shouldn't be any adding. I removed the alternator belt only and fired up the car. First thing I noticed was my idle AFR actual was lean, but upon a few short revs in neutral it revved up much cleaner and there actually weren't any AE blips on the log. So I guess my question is, is this a clear indicator the alternator is causing an issue? Or is there something in this test that Im overlooking that could explain the results I saw? I attached screen shots of both, with alternator belt on and without.
    Also just to add... I have the battery grounded to the block with a heavy cable, the block is grounded to the frame with a ground strap, the block is also grounded to the firewall with a ground strap. The alternator in question is a powermaster 150amp (1-wire) alternator.
     

    Attached Files:

  2. Fastmanefi

    Fastmanefi Well-Known Member

    Joined:
    Jun 4, 2011
    Location:
    Sonora, CA
    You should also have a heavy ground cable direct to the alternator case. There is no such thing as a single wire Alternator - there is always a return path. You have been relying on the mounting bolt. Same thing goes for the starter case.

    AE vs Map fuel can happen when the engine gets loaded by the alternator. This is common if you have the AE vs Map NOT starting at zero. This is a common error in the basic tune that FAST provides - no idea why they did that. The lower left corner must be ZERO.

    It's also common that the TPS% is after a calibration. It's a software issue, but it doesn't matter as long as he Max TPS% for idle, under idle parameters, is set to 2% - which it should be.
     
  3. J.K.

    J.K. Member

    Joined:
    Aug 7, 2016
    Thank you, I can certainly try adding more ground if that's what's going on. I assumed like many I'm sure that the alternator case/bolt to the head was sufficiently grounded.
     
  4. Fastmanefi

    Fastmanefi Well-Known Member

    Joined:
    Jun 4, 2011
    Location:
    Sonora, CA
    Check the AE vs Map table. That MUST start at ZERO.
     
  5. crash520

    crash520 Member

    Joined:
    Dec 16, 2016
    Even in Alpha-N mode?

    So most of us are using Speed Density Mode,
    Rich your saying the far left should be set at 0-0, then cheap up to the factory setting of 1.0 at the map rate of 4 on the table?
     
  6. J.K.

    J.K. Member

    Joined:
    Aug 7, 2016
    Mine was set to .8 right across the page. I had messed with it trying to eliminate the 1-2 gear shift stumble at light throttle. Didn't seem to make any difference on that but I will make sure its zero again on the left side. I'm going to work on additional ground for the alternator and starter and see how it works out.
     
  7. Fastmanefi

    Fastmanefi Well-Known Member

    Joined:
    Jun 4, 2011
    Location:
    Sonora, CA
    I never tune in Alpha-N.
    The lower left corner of the AE vs Map rate of change table must be at ZERO. The vertical axis is added pulse width (PW) in milliseconds (MS). Start at ZERO/ZERO in the lower left corner and ramp up to 2.4 MS at 31
     
    J.K. and crash520 like this.
  8. J.K.

    J.K. Member

    Joined:
    Aug 7, 2016
    Richard,
    Should the same apply for AE vs TPS Rate? Should it start at zero and ramp up the same way as the map AE?
     
  9. Fastmanefi

    Fastmanefi Well-Known Member

    Joined:
    Jun 4, 2011
    Location:
    Sonora, CA
    Yes it should start at ZERO too, bit it isn't as sensitive as the manifold vacuum when the engine is running. TPS usually stays put.
     
  10. J.K.

    J.K. Member

    Joined:
    Aug 7, 2016
    I did a wide open run and data logged it. Looking back at the data my TPS % never went past 80% on the log. I know for a fact it was wide open. The TPS dashboard does go to 100% on wide open throttle with engine off key on.
    Any reason it would of only reached 80% during an actual run? Is it a glitch in the logging software?
     
  11. Fastmanefi

    Fastmanefi Well-Known Member

    Joined:
    Jun 4, 2011
    Location:
    Sonora, CA
    Engine torque changing the throttle rod maybe.
     

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