i just bought a 96 integra that has a gsr swap. car runs great when warm but at a cold start it revs to 2500-3000 rpms and slowly comes back down. this is the first honda i have ever had. any ideas why this would be happening. thanks

 

Hondas, like most other cars, idle higher when cold to bring the engine up to operating temperature faster to reduce emissions. Basically, when you start a cold engine, your emissions are bad, cat is cold, and you can't burn off excess fuel efficiently. Now with that being said, 3000 rpms is a little high, so maybe your IACV is a little dirty. But overall I would say it normal. What ambient temp is this happening at?

 

^^^^this, you have nothing to worry about

 

thanks guys. what is the IACV and how do you get it clean

 

As mentioned 3000 RPM is high, there are more then a few DIY IACV cleanings on here and Google, search an ye shall find. 94

 

It could be your Fast Idle Thermo Valv. i have a b20b block with a b-18 head and had same issues cleaned the fitv and it ran better lower idle at start also
check this thread out wildoutwhitegsr did a great write up on it:

*** How-To*** Clean Your FITV aka Fast Idle Thermo Valve

Good luck (high idle during dry start isnt good in the long run)
DA's for life

 

https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/ link to the thread for FITV

DA's for life

 

an easy way to diagnose would be to cover the iacv port in the throttlebody bore with tape. start the car. if the idle is at a normal speed cold, problem is iac related. if not, it's all fitv. iac port is the upper of the 2 ports inside the throttlebody. if you only have one port, the car does not utilize a fitv and the problem could be the ect sensor or iacv.

another possibility is ignition timing. check timing with a light.

 

**** my ITR revs to 1500 rpm lol on cold starts. But i have a outlaw engineering spacer kit that puts a thermal spacer between the iacv. But it idles down to 900 quickly or i just start driving and the motor warms up better. But i always had a high idle on cold starts with most all my b series so id say its not that uncommon. Might need to be cleaned and put a new gasket.

 

High yes, but 3000 RPM is too high. 94