Have you had the temp sensor replaced? If your engine controls recieve feedback that the engine is too hot, it will go into limp mode, which is similiar to what you describe, it is like self-preservation. I would think that would be the first thing they looked at. If they have replaced it make sure they test it to ensure the replacement was not defective. Also if you replaced your wiring harness did they test the engine computer? If the harness became defective it could have messed up the engine computer from arcing or attenuation, causing certain systems to malfunction or not operate properly in the engine control computer. As your car is in Australia I am not entirely sure how your engine controls are configured, I am sure they are different than those we use in the US. Good luck!
Best Regards,
Brian

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Brian W. Heitman

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