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Thread: 7747 on a Ford 400 - running lean in open loop when cold

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    Fuel Injected! Dr_Grip's Avatar
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    7747 on a Ford 400 - running lean in open loop when cold

    Hi guys, I got my fuel tables pretty much sorted by now (city driving with a fully warmed up engine only in this log):

    Looks good to my untrained eye.

    But when cold, the engine feels powerless and weak. With my WB o2 sensor back under the car I quickly discovered the issue. Before the engine gets warm enough to enter closed look (CTS reading of 58C or something like that), she runs unbelievably lean with 16-ish AFR readings.

    What can I do about this? There must be a more elegant way than setting the fuel tables pig rich and let closed loop sort it out....

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    open loop afr vs coolent temp table.

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    Quote Originally Posted by ony View Post
    open loop afr vs coolent temp table.
    Thank you :)
    According to the table, AFR at fourty-ish degree celsius should be 13. I know that this is an estimate as the o2 sensor won't be used in open loop, but it is normal for the ECM to be that far off, i.e. should I simply set it to 10 and hope that gets me 13? Or is there another table/toggle that influences whether that table is used?
    Last edited by Dr_Grip; 03-06-2016 at 09:08 AM.

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    Here's the bin I am running, if it's helpful solving the issue...

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    Is it possible there is a criteria that is not being met that is preventing from actually initiating cold start.
    6395, BHDF, 7.4 BBC lightly modded now 6395 BMHM back to BHDF

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    Would that be "Choke - Temp thres for cold start"?

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    Quote Originally Posted by Dr_Grip View Post
    Would that be "Choke - Temp thres for cold start"?
    Nope, it was "Coolant Hot/Cold Thres." Works like a charm now.

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