2005 Honda Civic 1.6 - high idle after throttle body clean

[thatdude]

Hi everyone,

I had an issue with my honda civic (2005, 1.6 VTEC) the other week with a bad idle. RAC man diagnosed it as a bad idle control valve, and couldnt clean it properly there and then but got it good enough to drive to a mechanic. The mechanic has cleaned up the throttle body and the idle control valve, and now it runs well, however when coming to a stop and putting the clutch in while braking, the revs hang at about 1500-1600 rpm. When stopped, the revs will drop down to about 700 rpm (headlights off, higher with headlights on). Is there any reason for this? Is there anything I should be looking to do - does the ECU need to "relearn" the idle speed(s), and if so, how is that done?

Thanks

[Jimmyarm]

Assuming the system is the setup ford use, when you depress the clutch the iacv opens for emissions purposes.

The cure is normally to replace the iacv, cleaning it occasionally works.

Hopefully it is separate on that engine and not built into the throttle body as they can be expensive !

[thatdude]

Thanks for that - it has been cleaned (it was the cause of the initial stalling problems!). I think the issue might be to do with the throttle stop adjuster on the throttle body (i.e. the locknut and screw used to set where the throttle butterfly shuts). The RAC man fiddled with it in a manner to open the throttle slightly, it may not have been re-adjusted back to how it was before (i.e. "closed"). Idle settles down when stationary to 650-700 rpm.

I can't remember what size the locknut is, it might be smaller than any spanners I have in my took kit...