1994 Plymouth Laser Rough idle

1994 PLYMOUTH LASER
60,000 MILES • 4 CYL • FWD • AUTOMATIC
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CARMAN5000
  • MEMBER
  • 1 POST
After the car warms up, the engine has a rough idle. The engine speeds up for once second, then, slows down for one second, and on and on. How do I fix this?
Dec 24, 2009 at 7:10 AM
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MERLIN2021
  • ✓ASE Certified Mechanic
  • 17,250 POSTS
  • ASE Certified Mechanic
You may have a vacuum leak, get a can of spray gumout, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs! If that doesnt do it, you may need a new idle air control valve, it's bolted to the throttlebody
Dec 24, 2009 at 7:55 AM
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