idles rough hesitates jerks around 60 km an hr untill u bring up rpms

2008 FORD F-150
190,000 MILES • 5.4L • V8 • 4WD • AUTOMATIC
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BOOTY
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  • 1 POST
truck runs rough .. engine light is now on.. computer says cylin 3 and 4 misfires .. replaced egnition coils on 3 and 4 already .. also put new plugs in 2 months ago .. any more sugg thanks
Sep 27, 2014 at 4:22 PM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Have you replaced the two plugs with the new coils? Is the same code turning back on? Have you checked for vacuum leaks? These vehicles are known for a vacuum developing in a hose behind the throttle body that has a 90 degree bend in it. They dry rot and leak. Also, have you checked fuel pump pressure?
Sep 27, 2014 at 6:03 PM
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