1998 Ford F150 SPARK PLUGS AND WIRES

1998 FORD F-150
231,184 MILES • 6 CYL • 2WD • AUTOMATIC
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ALICEW0620
  • MEMBER
  • 1 POST
Last tune up was 100,000 miles ago. I have replaced the spark plugs and wires with the exact same part number as before. Now it runs worse than before. This truck has been running everyday. It has been running a little rough, so I decided to replace the plugs and wires. When the tune up was done before, the engine light would come on and I would go back to the garage. I was told nothing was wrong. The truck was running good, it was the light would come on. It does that now, but it will go off after a week, stay off awhile, it may come back on etc. I removed the plugs and checked to make sure the gap was correct and there were no cracks in the new plugs. Checked the wires and nothing appears wrong with new plugs. Why would it run worse? Should I put the old plug and wires back in?
Jun 20, 2009 at 7:00 PM
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BLACKOP555
  • ✓ASE Certified Mechanic
  • 10,386 POSTS
  • ASE Certified Mechanic
make sure you properly routed the spark plug wires. if not they could be crossfiring throwing the engine out of specs. make sure they are properly on the plugs and not loosly touching. measure the resistance of each plug wire.
Jun 23, 2009 at 10:10 AM
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