need some tuning tips.. '94 D16Z6
 

This new (to me) '94 Civic D16Z6 with a APEXi V-AFC II and a APEXi 4 func. turbo timer...

The car had a turbo on it, but was removed and returned to "stock". (right) I was advised that the likely cause of the idle issue was a leaky O-ring on the MAP sensor. I checked it, and replaced it with a better fitting O-ring. No luck.

The idle is irratic. Not exactly the fluctuating idle that is often seen when the Fast Idle valve goes bad.... It is unpredictable. Often the engine idles fine around 1,000 RPM, but sometimes, if you mash the brake pedal, or the clutch, the idle drops to around 550-800 RPM and fluctuates a bit, then just hangs around 700-ish. If you blip the throttle, it'll (sometimes) go back up to 1,000RPM. Also, when coming to a stop, the engine sometimes stalls. This is mostly seen on back roads when slowing from 55-65mph. Soon as the clutch is mashed in, the engine stalls completley. Bump the clutch, and she comes to life again.

So far as I can see, there are no vacuum leaks. The engine has an OEM intake manifiold, Megan header, no Cat, Unk airtube intake/K&N-style filter and the affore mentioned APEXi itmes. I thought that it could be an issue with the tuning because the car was previously running with a turbo. I have paid alot of attention to the turbo timer in it's air/fuel (O2) mode. It hangs around 14.5 when at idle and travelling down the road, and pops up to around 18.0-20.0 when off the throttle in gear at speed. It has been a long time, so I can't recall which end is rich and which end is lean.

I dont think this is anything I can adjust out with the V-AFC... though my experience is severely limited, and I just found and read the manual for this thing in .PDF format last night.

Anyone have some things I can look at? Suggestions?

BTW... when the engine idle drops, the TPS still shows 0.0% in the V-AFC.... O2 shows 14.5, even when fluctuating and at low idle. I tried the cheap trick of tightening up the throttle cable a bit, but that causes the idle to vary from 1,000 to 1700 RPM. Don'tlike that.