Stumbling startup

Discussion in 'General Tech' started by azurebluemach, Dec 7, 2015.

  1. azurebluemach

    azurebluemach New Member

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    Over the past few months, my Mach has developed a stumbling startup. It will turn over, then rpm's will drop so low, it almost stalls (it has stalled on first turn over maybe twice). After it drops like that, then it will slow creep up to about 800rpm, then finally you'll hear something open (best description lol) and it will go into high idle. Once it gets warmed up, she seems to be running normally, no misses, stumbles, or CEL's. I have not tried anything yet because I wanted some input first. I did try turning on/off a few times to get the fuel pump to run, but no change in startup.

    Here's what I've done most recently for typical maintenance purposes...
    -New IAC this past spring.
    -New JLT CAI air filter replacement (cleaned MAF when I replaced filter).

    Here's some other things to note...
    -No change in Bama tune
    -New gas tank in February (pretty sure they put in a new fuel filter)
    -New plugs this past spring

    Any ideas what I can start checking?


    IG: @rcodemach1
     
  2. lwarrior1016

    lwarrior1016 Moderator Staff SN95 Supporter

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    Bad IAC?
     
  3. azurebluemach

    azurebluemach New Member

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    I just put in a new Motorcraft IAC this spring, early summer though.


    IG: @rcodemach1
     
  4. azurebluemach

    azurebluemach New Member

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    Anybody else have any ideas?


    IG: @rcodemach1
     
  5. g36 monkey

    g36 monkey Moderator Staff SN95 Supporter

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    I would lean on the fuel delivery side, or possibly the MAF got damaged when you cleaned it?