So the story is I swapped the GSR engine into my DA like 6-7 months ago. Like all the other swaps I've done, it fired right up on the first try, which was nice since I had the engine apart to get the head freshened up and replace gaskets/seals/tbelt/water pump etc.

While driving everything ran fine. The problem was the car never idled right. It would idle around 1100 rpm, and when I'd give it gas and let off, it would bounce between 1200 and 1600 rpm for a little while, eventually leveling off at 1100 again. My first thought was a vacuum leak, but I couldn't find one anywhere. Then I went through the IACV stuff, cleaning it out and eventually replacing it with another one I had laying around. No change. I replace the ect sensor with a good one I had laying around. No change. Triple checked the timing, mechanical and ignition, eveything was fine.

I had been living with the annoying idle for a while, and then the other day I had a thought. I was using the original DA evap purge solenoid and charcoal canister. I thought maybe there could be a problem with the solenoid or something like an internal leak. I went out and bypassed the evap system so there was no vacuum running to it, warmed up the car, and there I go, PERFECT IDLE.

I just decided to rip out the whole evap system and block off the vacuum port on the manifold, now the car idles at 800 rpm and runs like a champ

I'm sure most of you don't care, but maybe this will help somebody that hasn't been able to find a vacuum leak or has a bad idle. I'm glad I found it because I was getting to the point where I didn't like driving my car anymore due to the annoyance.