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  • Idle speed

    What is the best way to set idle speed with the pro flo XT 3 Setup. When I go into Idle speed setup and push the close IAC closed it does nothing until I hit the ok button. Then it will idle at 500 or any setting I set it with the tablet. but what is the best way to setup idle. Should I leave it at 500 and set the Idle speed screw to desired rpm then set the tablet idle speed or?

  • #2
    Every engine combination is slightly different, so the IAC percentage will vary as well. Typically you will be between 5-20% with the engine warmed up in drive. After you have set Target Idle speed on the tablet, adjust the idle screw on the throttle body until the IAC% is between 5-20% and the idle is steady, then hit the Next button to calibrate the TPS. You may have to make another adjustment after driving a while and letting the system learn. Each time you make adjustments to the idle screw, make sure to reset the TPS so that it reads 10% after your adjustments.

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    • #3
      Not sure how I can do this. IAC percentage does not show up on my tablet. I tryed different tablets. I sent back the ECU and they went thru it. Still no IAC percentage in digital display. Whats up with that?

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      • #4
        It appears there's a bug with the app. We've been able to replicate it here on our end. It seems that closing and restarting the app usually brings the IAC reading back. Sorry for the problems with this - we'll work on getting it resolved.

        In order for idle control to work at all, TPS must read 10%. If it reads 11% or more, there will not be any active idle control. Once you have TPS correctly calibrated after setting the throttle stop, you can monitor how the idle feedback works by placing your thumb over the IAC hole in the throttle body to partially block air flow. As engine speed drops below target, you'll see the IAC position increase. If you then take your thumb all the way off, engine speed will overshoot the idle target and the IAC position will decrease.

        I know the instruction say to set the throttle stop to your desired idle speed and then set idle target to 50 rpm less in the app but I've always set the throttle stop to give me my min absolute rpm which would be less than desired idle speed and then target a higher idle speed. The reason being is that if for some reason the idle control stops working and is in the full closed position, the engine will still have enough air flow to idle. If you set a low idle speed that's only achievable because the IAC is open then when the IAC closes, the engine will stall. So on a V8, if the engine combo will allow, I'll set the throttle stop to 600-700 rpm and then set my target idle to 800-900 rpm.

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        • #5
          Originally posted by Nate S View Post
          It appears there's a bug with the app. We've been able to replicate it here on our end. It seems that closing and restarting the app usually brings the IAC reading back. Sorry for the problems with this - we'll work on getting it resolved.

          In order for idle control to work at all, TPS must read 10%. If it reads 11% or more, there will not be any active idle control. Once you have TPS correctly calibrated after setting the throttle stop, you can monitor how the idle feedback works by placing your thumb over the IAC hole in the throttle body to partially block air flow. As engine speed drops below target, you'll see the IAC position increase. If you then take your thumb all the way off, engine speed will overshoot the idle target and the IAC position will decrease.

          I know the instruction say to set the throttle stop to your desired idle speed and then set idle target to 50 rpm less in the app but I've always set the throttle stop to give me my min absolute rpm which would be less than desired idle speed and then target a higher idle speed. The reason being is that if for some reason the idle control stops working and is in the full closed position, the engine will still have enough air flow to idle. If you set a low idle speed that's only achievable because the IAC is open then when the IAC closes, the engine will stall. So on a V8, if the engine combo will allow, I'll set the throttle stop to 600-700 rpm and then set my target idle to 800-900 rpm.
          Nate

          Thank you for the well explained procedure. This is what I have done but since there is no IAC reading I am not confident its 100 percent correct. I sometimes have issues with starting the engine and have to hold throttle down just a bit for it to start. I beleive if I get the IAC at its lowest point car will start a whole lot better.

          I tryed going in and out of the app but theres no IAC. Sometimes IAC comes on in digital display when driving but it goes away fast also. This is why I always thought it was a software issue. The ECU that you guys went over did nothing. So what does this mean as far as software? Can you fix the software to have short and long term trims? Short trim and long trims is a big help in diag. I am also having trouble with a surging issue at cruise only but I am working thru this issue with Peter in tech.

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          • #6
            The work around to bring back IAC seemed a little inconsistent. I'd try the following:

            Disconnect and reconnect the app with the ECU
            Close an re-open the app
            Restart the tablet
            Power cycle the ECU

            Actually, I just spent the last few minutes testing the above and when in either the idle setup window or digital gauge display page, if I simply disconnect and then reconnect Bluetooth between the tablet and ECU, the channel values refresh and the IAC channel displays. When testing with a tablet, we also monitored ECU activity using our PC development software and can see that idle control is still active even though the IAC channel isn't being shown in the app so this appears to be limited to a minor software glitch.

            LTFT isn't a reported value but STFT is already reported as AFR Corr which is AFR Correction. Pay close attention to AFR, AFR Set Point, AFR Correction and Ignition Timing during periods of surge. Those channels should point you in the general direction of the problem.

            I could see an app update to fix this little bug but since Pro Flo 3 is a matured product, future firmware updates aren't likely.

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            • #7
              Originally posted by Nate S View Post
              The work around to bring back IAC seemed a little inconsistent. I'd try the following:

              Disconnect and reconnect the app with the ECU
              Close an re-open the app
              Restart the tablet
              Power cycle the ECU

              Actually, I just spent the last few minutes testing the above and when in either the idle setup window or digital gauge display page, if I simply disconnect and then reconnect Bluetooth between the tablet and ECU, the channel values refresh and the IAC channel displays. When testing with a tablet, we also monitored ECU activity using our PC development software and can see that idle control is still active even though the IAC channel isn't being shown in the app so this appears to be limited to a minor software glitch.

              LTFT isn't a reported value but STFT is already reported as AFR Corr which is AFR Correction. Pay close attention to AFR, AFR Set Point, AFR Correction and Ignition Timing during periods of surge. Those channels should point you in the general direction of the problem.

              I could see an app update to fix this little bug but since Pro Flo 3 is a matured product, future firmware updates aren't likely.
              Nate was this on the XT map or the single plane map? Seems the problem is more towards the XT map then the single plane map. My setup is the pro flo 3 XT.

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              • #8
                OK Nate. I did what you said and did get the IAC% to display in both adjustment and digital display. I set the idle as you posted. I cannot get IAC% to go under 50%. I can set idle to 850 or 1500 and IAC still reads 50%. Warm start I still need to press throttle just a bit to start. Stlll seems like a software issue on both issues. IAC will go up on fast idle when needed.

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                • #9
                  Doesn't the throttle body on the XT kit have a "secondary" air bleed adjustment screw?.....I've got too many EFI systems in my brain right now, so I might be wrong.

                  Anyway: If it does have the secondary adjustment. You crack it open a bit. This will let air bypass the throttle body ( just like the IAC ). So the idle speed will stay the same, but the IAC's percentage will drop down.

                  If other people are reading this, and they have the 4 barrel throttle body. Your seconday air bleed screw is on the secondaries.

                  At 43,861 MPH Elon Musk now owns the fastest car in this Galaxy

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                  • #10
                    Originally posted by BITE_ME View Post
                    Doesn't the throttle body on the XT kit have a "secondary" air bleed adjustment screw?.....I've got too many EFI systems in my brain right now, so I might be wrong.

                    Anyway: If it does have the secondary adjustment. You crack it open a bit. This will let air bypass the throttle body ( just like the IAC ). So the idle speed will stay the same, but the IAC's percentage will drop down.

                    If other people are reading this, and they have the 4 barrel throttle body. Your seconday air bleed screw is on the secondaries.
                    Throttle body has a brass screw on the top if thats what your referring too. But i still beleive its software. When in idle adjustment. You select close IAC. When I close IAC it still reads 50 percent.
                    Last edited by Scselt; 09-02-2018, 01:10 PM.

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                    • #11
                      You need to wait 12 seconds, or turn the ignition switch off, then on, or tape off the hole......like I said. I have too many EFI systems in my brain right now. So I'm not 100 percent sure how to get it to the closed position on this system......could be a bad IAC too.
                      At 43,861 MPH Elon Musk now owns the fastest car in this Galaxy

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                      • #12
                        Thanks Bite Me. I have waited and tryed cycling the key. But I have not tryed the idle bleed as of yet. But since the IAC is a output I would think if it was stuck at 50 percent the ecu would be reading low trying to shut it down.
                        Last edited by Scselt; 09-02-2018, 04:24 PM.

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                        • #13
                          The system cant "read" where the IAC is. It "tells" the IAC where to go........it uses math from the closed position, to figure out what percentage to show on the display.
                          It should always go back to closed when the motor is not running. Or when the motor is running "higher" then idle speeds ( TPS higher then 10 percent )

                          The main reason for getting it to "show" low numbers at your location. Is that at higher elevations, it will need to open more.....less air available.


                          With the key ON ( motor not running ) TPS should be at 10 percent or lower, and IAC should be at 0 percent.
                          If it's "not" displaying this. Pull out the fuse for the fuel pump ( you don't want to flood the motor with priming fuel ).
                          Turn off the key. Wait 30 seconds. Then turn the key to the ON position for 30 seconds.
                          If it still doesn't show the 10/0 percent. The ECU might just be sending it's last known value.
                          I would just reset the system.

                          If the system is displaying properly, and with the IAC set to OFF, and with the TPS showing lower then 10 percent during the idle speed adjustment procedure. Then Yes, crack open the air bleed.....as air bleed is open, you can turn down the TPS.
                          At 43,861 MPH Elon Musk now owns the fastest car in this Galaxy

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                          • #14
                            The ECU was already sent back to Edelbrock for this issue. They replaced the board. But I still have the same issue. So as far as a reset that has been done several times. Since Nate has reported there is a software bug I wonder if the bug is also causing the the display to report the wrong numbers. KOEO still reports 50 percent. Riding down the highway reports 50 percent. If I crank down the idle the IAC will go up so its working but how accurate is it working.

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                            • #15
                              That sounds like it's not resting the multiplier back to zero....when AIC is commanded to close: reset percentage to zero.

                              How about this:
                              Turn key ON for 30 seconds. Then turn OFF....this will put IAC at 0 percentage.
                              Disconnect battery for 20 minutes.......this will power down all the memory, in the "temporary" memory sections.

                              Threres basically only 2 other options I can think of. If that doesn't work.

                              1. The IAC you have might be out of spec.......I would try another one.

                              2. Send back the unit for repair again, with the IAC you have.
                              At 43,861 MPH Elon Musk now owns the fastest car in this Galaxy

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