As your integra gets older, and more mods are done to it your idle may begin to stray from the factory recommendation. This happens to many cars as they get older, and adjusting the idle is often part of regular maintenance intervals. Luckily, you don't need to pay someone to adjust your idle because you can easily do it yourself! 

The idle is adjusted by a screw on the throttle body, but it requires a few steps to adjust the idle properly. 

First warm up your car to its normal operating temperature, at this point it should be idling at its normal spot. Pop your hood and located the idle adjustment screw.
In this picture the screw is highlighted in yellow and I am pointing to it. This is on the side of the throttle body, right above where the air intake tube connects. 
If your idle has never been adjusted, it is possible that the screw will be covered up with some light rubber substance from the factory. Simply scrape it out with a thin screwdriver or a small knife. Before you start adjusting that screw, you need to disconnect the Idle Air Adjustment valve (IAC). The idle air adjustment valve lets in more air depending on what the sensors tell it, in order to help maintain a constant idle and prevent possible stalling. We want to disconnect it so that we can adjust the idle itself with out any interference. 

The valve is located behind the throttle body, facing the firewall.This is a picture taking looking directly down on the top of the intake manifold
 

There is an electronic connector on the bottom of the IAC valve, that you need to disconnect. While the car is running, Simply push down on the tab, and pull the connector downward and off of the valve. Be careful not to touch anything in the engine bay that could be hot, you could burn yourself. 

 

At this point the idle should drop at least 100rpm. If you don't notice a difference in idle, you may have a bad IAC and should replace it. 
Once the IAC has been disconnected you can turn the screw to adjust the idle. Turning the screw towards the firewall, or loosening the screw, will increase the idle speed. Turning the screw away from the firewall, or tightening the screw, will decrease the idle. 

You want the idle to sit right at 650rpm on the tach. Right between the 600 and 700 marks shown below. 
 
One you have achieved this, turn off the engine. Plug the IAC clip back in, and reset the ECU.

After you have let your ECU adapt, you should idle steady at 750 rpm +/- 50 when warm.