Well, I think you find yourself faced with the same question alot of us have asked numerous times. Why am I fixing this??? I spent 3k for it so the engine could crap out so I can spend 5k to rebuild it and make it the 6 million dollar car. Not gonna happen dude, stop inhalling the petro fumes.
Supra is a way of life. If the fires too hot, get out of the kitchen. Other than that dwy up your wittle tears and start turning some wrenches. Just like the rest of us. You can't sell it, because you have too much time and money vested into it. JDM engines, when are some of you going to learn????
There is a reason that particular engine is not slinging rubber from the rear of someone elses supra as we speak. For every 2 people I hear say something good about there jdm engine. There are 4 others complaining about them.
Fix it man. Fix it better than you would have ever hoped to then when it blows up again. Atleast you know you did everything you could to fix it.
Personally when I get done with my mkIII..., if it gives me any more guff, I'll park it in the barn and leave the title in the glove incase someone ever takes an interest in it, such as a gear oriented grand child or some shit.