I have a 97 civic with the D16Y8 motor. Motor idles high, 1500-1700 most of the time, especially after warming up. It also has a slight "dead" spot just off idle at around 2000 RPM, which also seems to get worse at random, but is always there to some degree. When its bad, it is hard to drive (5 speed) around town when you only have to be on the throttle a little bit. If you go up thru the gears accelerating hard, it's perfect, very smooth. I changed IAC yesterday, no change. No check engine light. According to a Haynes manual I purchased, this motor does not have EGR, FIT or IAB valve. What else should I be looking for?

 

You should recheck the voltage of the battery connected and just clean out whatever valve the motor comes with. I am not too knowledgable about 97 civic motor but this is a common problem in many cars. Hope i helped.

 

its your motor begging for vtec!

 

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It is you iac valve most likely, clean it or change throttle body

 

oops didn't read everything