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Thread: C950 Closed Loop Not Activating Consistantly

  1. #1

    Default C950 Closed Loop Not Activating Consistantly

    Hello, I've been on many various forums over the years dealing with Holley EFI. I have done many EFI conversions, but I prefer Holley whenever I can use it. Anyway, I have had a Commander 950 system on my 1964 Corvair for the last year, and it has been running pretty well. I sent my ECU to Woody over the winter to have the Firmware updated, which fixed the random high idle at startup. Of course being a tinkerer, when I reinstalled the ECU I made some changes to idling fuel and my WBO2 entrance conditions.

    I'm now having an issue, the controller will sometimes not go into closed loop, once the the entrance condition are met for temp, RPM & run time. If I cycle the ignition key, it will go right into closed loop.

    For example, today I was driving to work and I noticed a slight miss around 65 mph. I went ahead and popped open my laptop, and noticed the AFR was at 16.5:1, no compensation happening. For yuks, I turned the ignition key off & back on, and all was better. This would be about the 4th time I have encountered this. It's maybe happening more often, but my map is pretty close except in cruise, were I run it purposefully lean to help transition fueling, and warmup were I run it a bit rich, to account for unexpected accessory loading such as electric heaters and lights.

    Any ideas why Closed Loop would not be implemented consistently? Is the firmware fix violating my Closed Loop entrance conditions? Thanks for any help anyone can offer.

  2. #2
    Join Date
    Dec 2009


    This is a long shot, but try changing the TPS and/or MAP Noise Value (1-5) in Engine Parameters.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

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