When the TPS is unplugged the ECU will default to wide open throttle thus more fuel is likely being injected and that could be why the idle smooths out.

Why do you not have a CEL? Is it because you have a JDM?

 

I will double check TPS with the engine hot and report back the findings.

 

I do get the CEL on initial start up and if I unplug the TPS.

So if unplugging the TPS makes the ECU default to WOT and it runs smoother with more fuel then it's starving for fuel or getting to much air, correct?

 

Not sure if you tried getting any air bubbles out of the coolant system, have had idle issues from that as well.
Change Fuel filter, get injectors cleaned and flow tested, been reading the fuel pulsation dampeners can fail/leak which the vacuum line on the fuel rail sucks in fuel causing rich issue then the ECU compensate by leaning out and just back and forth
That's what I'm looking into on my fc3s now.

 

This makes sense. You might want to get the car to idle in the rough mode and try to find a vacuum leak by spraying the areas most likely to be sources of leaks.

 

I did make sure there was no air in the cooling system the best I could and I don't think there is , I've cycled the system cold to hot many times and released pressure at the rad cap, also the highest point of the cooling system is on the thermowax valve, I've been there too and nothing but fluid comes out so I'm confidant there isn't air.

I plan on changing the fuel filter ( hope it goes well as I've read the location is a pain )
And I will be removing the primary injectors and having them cleaned, I will ask to see the flow test ( buddy of mine has the machine ) at this point I don't think I need to clean the secondaries as my problem is idle.

Fuel pulsation dampener- I've read a few things on this but not much, I need to really check it out.
How would I check the dampner?

 

I have sprayed starting fluid in all the areas I can see which are associated with vaccumed and areas I couldn't see, no change in rpm and no fuel ping.

Just spoke with the old owner and he says it was running great last time he started it, until it idled up and down while warm, then died and wouldn't start, then I looked at it 2 months later and got it started with starting fluid and it smoked like crazy. Which I believe now was fuel.

 

Places where there are gaskets are also places you would want to check if you haven't already. Also, the secondaries are the easiest to access so it makes a whole bunch of sense to have these cleaned as well while your in the neighborhood.