Engine Performance problem
2003 Ford Taurus 6 cyl Front Wheel Drive Automatic 136000 miles
Engine cuts out when accelerating uphill and transmission downshifts at approx. 3000 - 3500 rpm. Car violently jerks back and forth as engine cuts in and out. Changed fuel filter, same problem persists.
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