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B20a3 idle spike to max 2 minutes after start?

339 Views 1 Reply 2 Participants Last post by  marshall.hazlett22
So I have a freshly rebuilt b20a3 in an auto 1990 prelude. When I start the car the it would idle at 3k then start climbing after a few minutes. I adjusted the idle screw and got it to idle around 1k on start but after a few minutes it still climbs. I don’t believe I have any vacuum leaks and I can’t seem to figure out the issue.
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PCV valve. Sits right on top of the motor. Mine was doing this last summer and this is the fix to my climbing idle.
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