Engine idle RPM fall when engine load increases


New Member
Hello. I'm struggling to find the issue with my Civic Idle RPM.
Vehicle: Honda Civic Ek3 1.5 (D15b engine)
Problem: The idle race (RPM) drop and gain slowly when AC turned on or engaging gear. The Idle RPM doesn't increase immediately instead it drops and then gain slowly. But When I break, the RPM response immediately.
What I did: I have changed the IACV with another used (recon) one, cleaned the TB (Throttle body). Checked air hoses for any leakage.
Question: Should I buy a new IACV as I'm assuming the replacement one (recon) may also weak or not fully functional.

Need your expert guidance =)
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