cords z31

ok so I own a 1984 Datsun/Nissan 300zx turbo 50th AE

My issue is that the car when cold started will shoot up to 2000 rpms for about 1 minute, after that it goes down to 1200 rpms. if the car is still warm, it will fire up and idle at 1200 right away.

The car will run fine and I have power and everything else seems to be working, is this a big deal?

things I have tried:
-2 different MAFS (is it possible both are bad?)
-all new vacuum lines
-new cap and rotor, wires are good.
-tried timing the car, its at 20 degrees, where it should be, but that is with a 1200 idle. if I try to move the distributor, one way it will just sputter and stall, and the other way just races the engine???
-sprayed brake cleaner all over the intake and the vacuum lines and no change in rpms
-tried un plugging the O2 sensor and the car runs the same with it plugged in or unplugged (could this be the problem?)
-2 different ECU's

I guess I can try and buy a vacuum tester kit, and a compression tester, not sure what else to try, maybe someone has had the same issue and can lend me any knowledge please and thank you, much appreciated, I will try anything that you guys suggest.

cords z31

my TPS was hooked up wrong, what a fail haha! I never thought of it because that's how I bought the car, it wasn't running due to ecu being fried, right from first start up it had a high idle, but the TPS wires fixed that.