2001 Pontiac Grand Am hesitation

2001 PONTIAC GRAND AM
198,000 MILES • 4 CYL • FWD • AUTOMATIC
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FRED57
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  • 1 POST
While driving pressing the accerlerator will cause a hesitation for a few seconds then it will catch and go. Idles a little rough when sitting at a stop. Have replaced fuel pump and filter, cat converter, spark plugs and boots.
Aug 13, 2009 at 3:37 PM
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RASMATAZ
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  • 75,992 POSTS
Dirty fuel injectors (cleaning the injectors often fixes this).
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
Wet plug wires
Aug 13, 2009 at 4:28 PM
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