1999 Mazda Protege Vehicle has unusual accelerations.

1999 MAZDA PROTEGE
140,000 MILES • 4 CYL • 2WD • AUTOMATIC
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AZNJAYX
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  • 2 POSTS
Okay, I can drive the car very well, even brought it to highway. I think there might be an escalating problem with the engine. I don't know if it's the brake pumps or the acceleration pump..

When I press on gas, it moves forward, and when I let go it should go forward bit naturally..well this one does..but when I do that, it speeds up and slows down again.. This youtube video exactly what happens, but moving forward. http://www.youtube.com/watch?v=a_C8YZXlvg8
Sep 2, 2009 at 1:34 PM
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RASMATAZ
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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
Sep 2, 2009 at 2:21 PM
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AZNJAYX
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What do mechanics call that when this happens to the engine??
Sep 3, 2009 at 12:43 AM
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