2004 Ford Focus Jerky engine at speed 50-70mph

2004 FORD FOCUS
152,000 MILES • 4 CYL • 2WD • AUTOMATIC
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FOCUS04
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Recently had a check engine light blinking indicating that the engine was misfiring the engine was running rough during idle and jerky at speeds of 50-70mph. discovered that the ignition coil was not working for the 4th ignition wire. Changed the ignition coil and replaced the spark plugs. Now the check engine light is off and the car runs better at idle, but it is still jerky at speeds 50-70mph. Any suggestions what to look at next?
Sep 13, 2010 at 1:30 PM
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RASMATAZ
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Lack of acceleration,chugging,hesitating,jerking,bogging,misfiring etc. could be caused by one of the following below:

Oxygen sensor.
Catalytic converter.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Knock sensor
Manifold absolute pressure sensor.
EGR Valve
Fuel pressure regulator leaking or defective fuel pump.
False air leakage.
Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.

Note:If it doesn't apply disregard it.
Sep 14, 2010 at 12:46 AM
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