Question about 2003 Chevrolet Suburban 1500

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Code po101, hard start when hot (have to hold W.O.T. to start) & stumbles on accelertion. Changed MASS sensor, no help.

It starts fine when cold. Have to hold it wide open throttle to start it when hot. turns over fine. Runs rough when it starts & stumbles when it's given gas. Sets code po101. Changed MASS air flow but same thing happens.

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  • rtde3 May 22, 2009

    Yes, and I have checked every vacuum hoses.

  • rtde3 May 22, 2009

    OK, I tried the idle control & it work fine. I did unhook the Map sensor & it ran better!? Do you think the MAP sensor is bad? That was one of the things listed under code po101.

  • rtde3 May 22, 2009

    I did clean the mass air flow & it did not work. I put a new one on there & it did not work.

  • rtde3 Jun 04, 2009

    OK, I have been out of town but i'm back.
    I did put the MAP sensor on there & it's doing the same thing. I also put a new ground cable from the motor to the frame.

    So after a new mass air flow, MAP & ground cable it's still will not start after its warmed up unless you hold down the gas pedal to the floor. And it stumbles when your crack the thottle. And the ck eng. light is on giving a code PO 101.

  • rtde3 Jun 10, 2009

    It turned out to be the Temp sensor! It runs fine now!

  • Dar
    Dar May 11, 2010

    If you changed the maf, and it's still doing it, again, i ask, did you put a new air filter in it?

  • Dar
    Dar May 11, 2010

    Sure, give it a try.

  • Dar
    Dar May 11, 2010

    Okay. Some more things you can check - engine ground connection. Loose connection in the ignition system. Faulty idle control valve . To check the idle control valve- When the engine is warmed up, put it in gear, turn on the air conditioning, turn your steering wheel back and forth. The idle should remain steady,or increase slightly. If the engine stumbles or stalls it's no good.

  • Dar
    Dar May 11, 2010

    Have you changed your air filter?


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Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4.0 seconds.  I would try cleaning out your MAF sensor with some carb cleaner and reseting the check engine light to see if it comes back on.  If it does, get back on here and let us know and we will walk you through some other things you can try.  Cleaning it out will be the easiest/cheapest thing for you to try right now.  Good luck.  Thanks for an honest rating and for using FixYa.   

Posted on May 22, 2009

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