Possible vacumm leak?? Need some help

What up G2,

I have a 90 integra LS with a stock motor, DC sport header, Greddy exhaust, and Thermal intake manifold gasket from Hondata. The car is converted to OBD1 and running on Hondata S300. IT has the stock LS base map provided by Hondata loaded on it. The car drive perfect and my A/F are looking really good in closed loop. I haven’t changed anything really on Hondata.

I know my FITV is probably acting up b/c the car idles a little off when the engine is cold. I’m going to take it off and clean it up to see if that corrects any idle issue while cold. The problem I’m having is that when I am coming to a red light or anythign that I have to stop for, the RPMs seem to raise up a little when I get off the gas and push in the clutch. I can post a video later if this doesn’t make sense.

Basically, I’m driving down the street and I see a red light a head so I get off the gas and push the clutch to coast in. The RPM’s drop to about 1k rpms and then raise up to about 1500rpms and then slowly come back down when the car comes to a stop. IT happens everytime I push the clutch in. I can see the needle moving around a little bit at idle when the idle does go down to about 850-900rpm (I have the min. idle set to 850rpm via hondata.)

Would this be an indication of a vacumm leak? Could my FITV be causing this slight flux in the RPM? Other than that, the car runs and rides fine. I’m going to spray the intake side tonight to see if I have an obvious leak in a hose or something.

On Hondata my vacumm is reading in the 19 - 20 range. Sometimes it’s in the 18’s. I thought I should be in the 20’s with an LS motor on stock cams. I’m also idling in columns 3-4 instead of 1-2 when I check my laptop. Maybe there is a compensation accuring that is setup on hondata??

Any help would be appreciated.

Thanks,
Ryan