I actually have sort of the same issue with my car

This is what I've done so far:

- Oil change
- Oil filter
- Coolant
- Spark plugs
- New Battery
- Reset ECU
- Cleaned Throttle body
- Cleaned IACV

The car cranks but won't turn over!!!

I've spoken to a mechanic at Toda Performance and done some extensive research (google ftw), from what I can tell I probably need upgraded fuel injectors as the stock ITR ones (240cc I believe) aren't as good for whats been done to my car.

I believe my car sits around the stage 2 area (may be close to stage 3) of modification and I've read to expect a high/rough idle, on that note higher stages of modification will require upgraded parts (no shit sherlock :P)

Regards
- John

p.s I bought my itr already highly modified, but I don't regret it as I would never have put as much effort into researching as I have done so far