Idle speed- 89 Sentra

[JoeKansas]

I've had this '89 Sentra for 3 or 4 months now. It has the GA16i engine. Throttle body injection. A few months ago, I replaced vacuum hoses. Everything ran fine after that. It still runs fine. Recently, at startup, it idles too high for my liking. I could understand if it was cold out. It has cooled off outdoors a lot, like down to around the 60's in the morning, but that isn't cold as far as causing the engine to go to high idle to warm itself up, I don't think. It has no tachometer, so I really can't tell you what speed it's idling at. I would guess 1500 or so. After it starts, I've been going ahead and putting it in drive to put a little load on the engine to slow it down some. After a couple of minutes, it idles back down where it belongs, and all is well. It just does this after setting for an extended period of time- after the engine has cooled back down to ambient temperature. I believe the screw on the ECU is dual purpose, to check for trouble codes and be an idle adjusting screw (at least that's what it says on the sticker surrounding the screw). It is in the fully counter clockwise position, just where it was when I first checked for trouble codes months ago. I haven't changed its' position any. Surely this adjustment has nothing to do with this temporary high idle condition?

[NISTECH]

That is not an idel screw, it is to put it in base mode so you can adjust the idle. So no that wont be your problem. The car should have a fast idle when cold in the neighbor hood of 1200 to 1500 rpm, then once it reaches operating temp it will drop to standard idle.