What can be the problems for a 97 Honda accord idle fluctuate
Vacuum leak, bad IAC, worn rings, worn valve guides, valve clearance is off, the ECU is too old to operate properly… I could go on and on buy why don’;t you help by telling us the very most basic piece of information - what engine? Also is the check engine light on? How many miles on the engine?
If there’s air trapped in the cooling system, and it passes by the coolant temp sensor for the computer, this can confuse the computer where it causes the idle to fluctuate.
247000 miles 2.2 engine of sedan 1997 Honda accord p0505 code iacv but I replaced the new iacv still has problems
If you are still getting the P0505, suspect the wiring and connector, especially on a 22 year old car. Also suspect dirty IAC passages or a worn out throttle body.
As for the surging, everything I mentioned in my first reply still applies as well as @Tester 's post.