How do I lower cold (aka fast) idle only?

[MakitaDiesel]

'04 K24a2 with Accord cable throttle body in an '01 Insight. No surging issues like many others report, idles warm at a steady 750 rpm, tuned out all knock.

All I want is for the cold idle aka fast idle to be lower than it is now (2k-ish). If it's below 40* outside and with the aftermarket exhaust the noise and high strung nature seem unnecessary. She's geared kind of short so when I first start it up and put-put around the parking lot it's trying to take off with such a high idle in gear so I must ride the brake. Again, once she's warm there are no issues and I'd dare to say she's quiet. I attempted to slide the idle duty cycle many clicks to the left which lowered the RPM at first crank to below 1.5k but also causes it to die when warm when coming to a stop as the RPM's bottom out. Only cold idle needs improvement, 1-1.2k would be ideal.

Mak

[Spunkster]

Have you set the idle properly with the idle valve unplugged?

[MakitaDiesel]

Unplugged? I was only aware of the idle relearn procedure that involves leaving the valve plugged in for K20/K24.

Back in the day on my older Hondas I'd unplug the IACV or equivalent and let it bottom out to 400-500 rpm set by a screw.

Mak

[Hondata]

You need to do something equivalent on the K series engines to the B where you stop any air flow through the throttle port and check the idle drops right down. This verifies that the high idle is not caused by air leaks. On the B series you unplug the idle controller. On the K series often you can just block the idle port in then the throttle body by holding a piece of rubber over it.

On your engine do you still have the fast idle valve? You can easily clamp off the vacuum hose from that valve to verify this is not the cause.

[MakitaDiesel]

I will try that (block off the port) next time she needs something that involves removing the intake. She is daily driven but as a beta test project car it won't be long I can assure you.

To my knowledge all '03-05 Accords are cable driven and have an idle air control valve that mimics the purpose of a fast idle valve. I'll be sure to disassemble and clean it during the port check. Will report back after both are done, my guess is sometime in the next month.

Thank you both for your assistance.

Mak