ok I have found some pics of it and upload a youtube clips for you guys to see. 

This clip taken two days after I picked MR2 up from Terry. this is what its doing. (March 2013)
http://www.youtube.com/watch?v=2FiND4LHu6k&feature=youtu.be


This clip was taken the day before it died on me. At the beginning of this clip is where I stopped at the end of the street.  it idle near 500rpm  .. then I drove into my driveway (please accused the steering wheel turning, while I hold this iphone) , it idles at 1000rpm.   (31st Oct 2013)
http://www.youtube.com/watch?v=8usJ1ydXDdE&feature=youtu.be
 
 
Then the next day it idle at 500rpm when i first started it so i put air con to keep the RPM up to 1000rpm (terry told me to do this method) where it's a bit driveable at cold start. I drove for about 8 mins then stopped at road work....  MR2 decided to shut down and wont start at all. :(

So I hope this may give you some idea of whats wrong with it. 
It looks like that I only driven  1500ks in 8mths.....  I don't enjoy driving this thing anymore :( Hence low ks during this time.

let me know if these youtube clips work on here 
 

Yep, clips are working fine.  Actually, I'm not seeing a problem with the idle.  OK, maybe a whisker low, but it's doing what I would expect to see.  It idles smoothly, then when revved it bounces low, then returns to the original idle point.
 
The corrosion on the ECU case could go either way.  The case could still be sealed, and the internals are all fine.  OR it's not, and you've got yo'self a little box of hassle . . .

dennis the menace
Yep, clips are working fine.  Actually, I'm not seeing a problem with the idle.  OK, maybe a whisker low, but it's doing what I would expect to see.  It idles smoothly, then when revved it bounces low, then returns to the original idle point.
 

 
Yeah, i'd agree with that. There is another background noise which makes the engine hard to hear, sounds like the internal fan to me that keeps tapping.
 
Like DTM says, when you rev it the needle bounces low but when its settled it looks like it idles at around 800rpm.
 
The cold start with aircon idea sounds a bit odd, but the change in rev's is what i'd expect with aircon on or off. 
 
Car shutting down totally, well thats a problem. 
 

yeah it has a mind of its own ...  sometimes 500  and other times 800  and 1000. 

hmm ok ...  i guess theres more to find out tomorrow.. or so . i'll update it when i know something .

I wonder if the idle air controller valve is gunked up or not functioning correctly? Its attached to the underside of the throttle body on a 3sgte so i'm guessing it would be there on a 3sge.
Can you remove it, clean it & then reset the ecu?

Mrskylighter
I wonder if the idle air controller valve is gunked up or not functioning correctly? Its attached to the underside of the throttle body on a 3sgte so i'm guessing it would be there on a 3sge.
Can you remove it, clean it & then reset the ecu?

I'll look into that skylighter . 

Update. the car is running now.  It was the ECU that was faulty and repaired. So another $750 out of my pocket . 
cheers everyone .

So you were sold a $5500 engine conversion with a faulty ECU?
And then had to spend another $750 to fix it?

yes thats right ..... 


sigh 

There were no suitable second ecu's on the market at the time or you just didn't want to take the risk?