Won't start til 2nd try and lost 2mpg

Discussion in 'Technical Department' started by keithfa, Apr 20, 2017.

  1. keithfa

    keithfa New Member

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    I don't have to post here much since my truck is a little older and I can normally find an answer with the search but not this time. 2007 NNBS Sierra crew 4x4 with the 5.3 flex that just hit 100k.

    For 6 months now I turn the key, let it go and the starter spins for the 6 or 8 seconds it's supposed to but it doesn't start. Second crank it starts. 95% of the time this is what happens and 5% of the time it will start on the first crank like it's supposed to. It's not the fuel pump or fuel pressure. I can cycle the key on and off 12 times before I try to start it and the same thing happens.

    Since this has started happening I have lost about 2mpg in addition. The truck does everything else like it should. No power loss or hesitation in the motor. Any insight would be much appreciated!
     
  2. Bushwacker

    Bushwacker GMFS Member

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    How's your air filter?

    Sent from my HTC One_M8 using Tapatalk
     
  3. keithfa

    keithfa New Member

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    Changed it about 2,000 miles ago. All of the routine 100,000 maintenance has been done and I'm at about 103 right now.
     
  4. barrrf

    barrrf Website QC

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    Get you a Torque App and BT module and log the start ups. You should be able to log the relevant sensors for this. Maybe fuel pressure sensor?
     
  5. keithfa

    keithfa New Member

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    I kind of dismissed fuel pressure as a reason since I can turn the key to prime 3 or 4 times, and I still get the same thing. First time no start, second, no problem. But I guess it didn't dawn on me that it might be a sensor. maybe I'll give Torque a shot.
     
  6. sprog

    sprog New Member

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    What did u find out I am having similar issue.
     
  7. keithfa

    keithfa New Member

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    I haven't found out anything yet. My phone is an IPhone so I can't get Torque, trying to track down a buddy with an Android
     

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