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marcy 6/30/2012
1999 Mazda Miata 10th Anniversary 4Cyl1.8L - Engine
why does my car hesitate when i step on the gas. this happens after sitting at a stop light for a few minutes.
the check engine light is not on. it is quirky...never know when it is going to act up. and it is driving me nuts.
1 Answer
  • Jimm
    Jimm 7/1/2012
    First step - have the check engine scanned - for free - at any local auto parts store, such as; Advance Auto, Auto Zone, NAPA. The stored fault code will give specific information about the component to check or repair to perform.
    Then, post a reply with the specific code to Auto MD for further assistance.

    Possible Causes of Engine Hesitation or Stumble:

    Dirty fuel injectors (cleaning the injectors often fixes this).
    Dirty / clogged air filter element (change the air filter)
    Bad MAP (manifold absolute pressure) sensor
    Bad TPS (throttle position) sensor
    Bad or dirty MAF (mass airflow) sensor
    Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
    Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
    Bad gasoline (fuel contaminated with water or too much alcohol)

    Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

    Dirty or worn spark plugs
    Bad plug wires
    Weak ignition coil


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