Idle high then idle rough

1987 HONDA CRX
215,000 MILES
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JDYAL2
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I have the fuel injected crx si. I had an aftermarket intake when i bought the car so i put the OEM intake back on from the junkyard. After i did that the idle goes up to 2500rpms when cold and bounces from 1500 to 2000rpms. when it gets warm it goes to 700-750 rpms but bounces from 700-850ish and every once and a while drops to 500ish and feels like it wants to die and rattles everything. but never actually dies. it did the same with the other intake too except the high cold idle. I replaced the distributor because i thought that was it and nothing changed. it also has a new fuel filter but i installed it properly i believe.
Oct 25, 2011 at 9:00 PM
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ASEMASTER6371
  • ✓ASE Certified Mechanic
  • 52,796 POSTS
  • ASE Certified Mechanic
you have a vacuum leak from somewhere. i would have a shop smoke test the intake and find the leak. it may be something as simple as that.

Roy
Oct 25, 2011 at 11:39 PM
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KHLOW2008
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  • ASE Certified Mechanic
Check the idle adjustment screw and cold start valve for vacuum leakages.

Ensure the coolant hoses to the cold start valve is not clogged and there is sufficient coolant in system.
Oct 26, 2011 at 8:19 AM
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