just installed head/cam/ported tb. my car would idle around 2000 rpm with ac off in neutral. found out i had a vacuum leak. service engine light came on. clamp hose back on and engine light went off but still had high rpm in neutral. drove it for a bit and went away for now. now when i turn ac on it does the same thing. goes to 2000rpm in neutral and stays till i almost stop. doesnt do it with ac off so far. going to test in morning to see if problem comes back.

throttle cracker is zerod out. got a friend looking into the tune to see if thats causing it. will let you know in a few days.

 

I had the same issue after a Fast92/95 combo install. Cracker was zero'd (made no difference anyway) and AFR was perfect. I took away some idle air and bam, huge difference. I have not tinkered with it anymore but I'm sure I can fine tune it. I just took away like 10% to see what would happen and it solved my problem by about 90%.

 

Having a very similar problem. Mine idles high around 2k when I press the clutch. I don't have a speed sender going to the computer, so it stays high when I stop. To drop the idle, I tap the skinny pedal and it will fall back down to normal. As soon as I put it in gear and get going again, right back up to high idle. It pulls the car as if in cruise, as mentioned before, when I put it in gear and get going.

I'm thinking a vacuum line behind the intake. I had to move one recently when I installed a new brake booster. Anyone find a cure for this, before I go digging?

 

Here's a video detailing. Haven't found any vacuum leaks yet, still checking.

https://youtu.be/prJlKcVaToE

 

And fault codes

 

I cleaned my throttle body with carb cleaner and the MAF with sensor spray.

Seems unlikely that this is what fixed my problem, but it is now completely normal.