1986 Ford Thunderbird Rough idle - engine light on at start

130,000 MILES • V8 • 2WD • AUTOMATIC
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TALMECH
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  • 1 POST
1986 5.0L EFI low output (cleveland i think). Engine starts perfectly and revs high for a bit but then settles into its idle. Idle is rough, it wants to stall (it has, very rarely). Rhythmic sound (mmmhhhhmmm . . . . . mmmhhhhmmmm). Check engine light is on at startup, disappears after a few (2-5) minutes of driving, but the rough idle remains at stoplights etc. Other than idle problems it works great!!! Oil, oil and air filter and sparkplugs are changed regularely. Thanks guys!!!! What a wonderful site.
Sep 17, 2009 at 12:57 PM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
Try pulling code/s out of the computer with and w/o the light on

Check and test the idle speed control motor,throttle position sensor, manifold absolute pressure sensor, and clean out the EGR and PCV valves-
Sep 17, 2009 at 9:21 PM
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