OK! I still havent been able to figure out what the hell the problem is. Me and Joe installed a 64mm Throttle on my car and ever since it had this surging Idle.

The surging idle happens when you rev the car in neutral and let the RPMS Fall. It will search for Idle for a little bit and eventually even out a little with minor idle surging.

Heres what Ive done.

Check Rechecked and Checked again that the gasket and Bolts are properly and tightly torqued down. Ive sprayed Brakecleaner around the throttle housing with no luck. Disconnected the IAC valve and follwed through the IAC diagnostic in the Helms book. There is Suffienct Coolant and a full reseivor. Checked the TPS voltage at Idle to be .503v. Checked the Throttle cable There is good sealing in the TB. Reset the ECU various times and waited till the 2nd fancycle to restart the car. No luck. Checked the vacum lines in my car for leaks none at all. Even put back the Original TB in the car only to have the same problems. Joe messed with the Idle screw with no luck. Im out of Ideas. Did I miss anything? Suggestions?

 

did you check all your vacum hoses?

 

The gasket and butterfly was checked more times than I care to remember. There doesnt appear to be any vacuum leaks in any of the lines. Its funny because last night it would idle funny then it would just go away. Towards the end of the night it didnt do it anymore. Ill check the IAC screen Next. Keep the suggestions coming

 

dont feel bad mine does this too. and my car knows when its night and when its day... doesnt matter what temp it is outside... we set the idle to 1k on the hondata i get 750 during the day and 1k at night...