New Idle issue, imagine that!!

[Ben]

This happened out of nowhere.

I have a FIAV block off plate that still allows me to use my IAC. For the longest time, when I had a cold start it would idle a little higher til it started warming up. Then it would drop to 900-1000(what my chip is set to). perfect, I loved it. Now no matter what I do it will not idle, it trys to idle at 400 or so if it even tries. Also when I would start slowing down, push the clutch in and coast down to a stop in neutral the RPMs would stay a little high, then a second or so after the car came to a complete stop, it would drop to 900-1000. It doesn't do this anymore either.
I tested my iac, and all the coils tested ok. I have the black plastic version. I tried another one I have that tested ok also, same results.
When I had my ecu recapped and socketted, it looked brand new inside.

I put a FMIC on a few weeks ago, and it idled a little low right after I put it on. I adjusted it up just a tiny bit, and it worked great for a week. One time I started it, it started doing this. I also recently installed an aeromotive AFPR. It still worked fine for almost a week after installing that.

I don't have power steering, and I have the PSP switch wire taped up so it's not touching anything.
I have a 2g tps with a built in Idle switch that works.

Any suggestions??

 

[Ben]

I wanted to add more.
When it 1st started to happen, it was surging bad at idle. I thought I fixed in turning the idle down. turn the car off and back on, then it was back to surging. That's when I switched to the other IAC. And from then on, it wouldn't even try and idle. tonight I was driving around slowly turning it back up and thought I was getting some where. It was 1/2 ass idling ok at 900-1000, but still sometimes falling to 600 ot so. Then one more little adjust and the biss screw was all the way out. nope something has to be wrong, I shouldn't have to go that car out. So its idling around 900-1000 with the lights on, as soon as I get home and turn the lights off, BOOM 1400. Turn on the lights, BOOM 900 RPM. wft??

That ground strap that goes from the batter to the body has been ripped off for a long time. I'm going to get something to fix that. And I think I'm going to solder in a larger ground wire going from my TPS to my IAC to the firewall.
I have a somewhat new Mitsubishi alt, so it's not the voltage dropping from the alt being weak or something like that. I just need to look around some more....