1998 Ford Expedition engine runs rough during acceluration.

1998 FORD EXPEDITION
150,000 MILES • V8 • 4WD • AUTOMATIC
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CKULA
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  • 1 POST
hello, 1st I changed fuel filter. Then was told this car hasnt ever had a tune up? 2nd changed spark plugs...
Ran great for two weeks then problem came back,pulled trouble codes said miss fire in cyl. 3 swaped coil pack with cyl. 1 that cleared codes ran fine for a few days. Now problem came back worse,Im at a loss today the check engine light finally came on. what should I do next? I finally beleive the problem is circled and highlighted blue!!!
Jul 12, 2009 at 9:01 PM
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JACOBANDNICKOLAS
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IF the check engine light is on, you need to scan it again to see if the problem has changed. The coil pack may be weak or I have actally seen the rubber boot on the coil pack burn through allowing the spark to short out on the inside of the valve cover resulting in a miss. Did you check the rubber boots for any signs of this? Usually there will be a gray spot where the spark arks through. Give that a check to see if that is the problem. Believe it or not, it is more common than many know. Most mechanics will say you need a new coil pack when only the boot is bad.
Jul 16, 2009 at 11:02 PM