Tacho drops to 500rpm

The longer you let it idle with no accesories on the better the idle quality will be. Earlier systems require a good minimum half haour to an hour to learn a perfect idle.

Well, i dont know if its still relevant now...
but, saw the mechanic awhile back with that problem,
and he diagnosed it as a broken iacv.
didnt replace it.. but just adjusted the bypass valve to keep the revs from dropping so low.

it sort of masks the problem now... like as in the revs dont drop low...
but it always feels like its not idling as smooth as it used to..

would it still make sense to try what u (Dr Honda n Aaronng) suggested?

Clean out your TB.I reckon that's what's causing it.I just had the same thing happen in my Civic.

thx for reply guys,

i've just chucked in half a bottle of fuel injector cleaner to see if it helps, no change.

looks like i should just take off the TB and give it and the IACV a good cleaning + what dr honda suggest.

now question is, the gasket, would that still be reusable or should i just get a new one ?

If the gasket is not torn you could propably get away with it. Also when you reset the ecu do it when its hot so it get a good re learn. Good luck. :thumbsup:

I just used the original gasket.11 yrs old.All good.

Clean the IACV as well. There is a DIY on it here.

A++ aaron! would pq but cant =) well called for

could this be caused by faulty O2 sensor?

just an update guys,

i've just cleaned the IACV + TB and took her for a drive, its fixed !
although wen i come to a stop now, it comes down to 1000rpm, for like a split second before goin to 700rpm (alot better than almost stallin tho haha)

ive got the car idling after a ecu reset as im typing this, so hopfully should be ok.

also replaced the gasket too.... just FYI, the old gasket was a bitch to get off, ffs had like two cramps in my hands -.-"

ohh, anyone else wanting to attempt this, dont be a lazy kent and leave the throttle cable attached, i tried to take off the IACV while the cable was attached, and spilt coolant into the engine bay -.-" lucky i put a bag over my CAI pipe ....

anyways cheers to all thos who have helped. much appreciated !

steven