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Thread: Cold start surging idle

  1. #1
    Tuner in Training
    Join Date
    Feb 2020
    Posts
    32

    Cold start surging idle

    Tuning is going well but I suddenly have a surging idle at cold start. Rpm and spark surge for the first minute or so of running and then the idle evens itself out and there are no more problems during driving. If started while the engine is warm the surging doesn't happen. What could be causing this or what should I adjust to help with it?
    20-02-24 09-11-53.hpl
    VE Tune Part 2 run 52.hpt

  2. #2
    Advanced Tuner
    Join Date
    Feb 2015
    Location
    Perth, Australia
    Posts
    974
    cold surge E38 is because its too rich. by at least 15-20%

    look at changing open loop EQ ratios back to 1.00 in cold areas and setting the open loop IVT gains closer to 1 in cold areas also.