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Thread: First start, 7060 to 7427 Conversion - Crazy rich at idle

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  1. #1
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    Quote Originally Posted by dave w View Post
    I would try injector flow of 78, with the expatiation that all BLM averages will increase from rich (less than 128) to a number much closer to 128. An injector flow rate that has some VE cells with BLM averages rich and some VE cells with BLM averages lean is a good setting.

    The Manifold Air Temperature settings are correct, and -40 temperature is correct too.

    dave w
    Thank you, Dave. I've gone up to 78 on injector flow rate - it improved things, but still very rich. No BLMs are above 128, most are in 110s or lower. Should I just keep increasing flow rate in 4 lbs/hr increments until I see some BLM values over 128?

    One other thing: at warmed up idle, closed loop, spark advance is jumping around a ton, all between 15 and 25, mostly between 15 and 20. Something to be concerned about?

  2. #2
    Super Moderator dave w's Avatar
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    Verify the O2 sensor is working correctly by looking at the voltage swings in the "Monitors" screen of TunerPro RT. If the O2 sensor is working correctly, then increase the injector flow another 4 lbs. It seems unlikely the injector flow would be greater than 86 lbs.

    The idle SA is somewhat concerning, swings of a few degrees is normal. Idle SA swings of 10 or more degrees is concerning.

    dave w

  3. #3
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    Quote Originally Posted by dave w View Post
    Verify the O2 sensor is working correctly by looking at the voltage swings in the "Monitors" screen of TunerPro RT. If the O2 sensor is working correctly, then increase the injector flow another 4 lbs. It seems unlikely the injector flow would be greater than 86 lbs.

    The idle SA is somewhat concerning, swings of a few degrees is normal. Idle SA swings of 10 or more degrees is concerning.

    dave w
    Thank you, Dave. From what I know about the NBO2, it looks like it's working normally by watching the monitor. Pretty regular swings from 100 to 900 mV. It does plateau low or high for a few seconds at times, but then starts swinging again. I'm going to bump up flow rate to 82 lbs and see what happens.

    As for SA, I also plotted that on the monitor and it looks more normal there. Previously I was just watching it on the analog gauge in TP dashboard. At the end of the drive I let it idle for several minutes in closed loop and the SA stayed pretty close to 17-18, with swings of a degree or two either way, but very consistent. It did bounce around quite a bit more if I rev'd it, but I think that's expected. I also noticed that SA was very large (40-41) on cold start up and linearly decreased as engine warmed. Weird?

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    Quote Originally Posted by dave w View Post

    The idle SA is somewhat concerning, swings of a few degrees is normal. Idle SA swings of 10 or more degrees is concerning.

    dave w
    Finally got back to tuning today and noticed that today's log and the most recent one before that Code 43, Knock Sensor Circuit is being set. I haven't had a chance to look underneath yet, but I'm wondering if my knock sensor circuit is open or broken. I've had problems with wiring down there by the exhaust before - maybe it melted. Could an open on that wire cause fluctuating advance at idle?

    Haven't ruled out traditional ignition problems, either, e.g. plug wires, distributor, coil, etc. At hot idle I can hear slight fluctuations in the exhaust note that seem to correspond to fluctuations in spark advance.

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    Checked the wire from PCM to knock sensor: not melted and there's continuity between the PCM connector (B15) and the connector at the KS. So now I guess it's time to do the full diagnostics on the KS circuit? Some more data:

    - KS is brand new Delphi, AS10016.
    - First data logs after '7427 install did NOT flag code 43, or any other code.
    - SES lights intermittently, but rarely and for a short time. Has lit after both accel and decel as well as at cold idle.

    Maybe the connection at the KS is just loose? Thoughts on what to check next? It seems like there are some voltage checks one can do on the KS circuit, but I've read some conflicting data on the 'net.

  6. #6
    Super Moderator dave w's Avatar
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    Maybe if the KNK was temporarily disabled in the chip will help with the diagnostics troubleshooting.

    dave w

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    Quote Originally Posted by dave w View Post
    Maybe if the KNK was temporarily disabled in the chip will help with the diagnostics troubleshooting.

    dave w
    Thank you, Dave. I can do that. But sorry for my ignorance, what will that tell me? Should I expect to see a more stable spark advance if I disable?

  8. #8
    Super Moderator dave w's Avatar
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    Quote Originally Posted by Daveo91 View Post
    Thank you, Dave. I can do that. But sorry for my ignorance, what will that tell me? Should I expect to see a more stable spark advance if I disable?
    Yes, disabling the KNK might provide a more stable spark advance. Possibly indicating the Memcal knock filter circuit is faulty, or PCM is faulty / PCM not faulty.

    dave w

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