I had a case where my distributor was sparking but wouldn't crank,(no matter how much i rebuilt with working adn new parts) until I just replaced it. Then it cranked up. Recheck that again, and you mention your car got tune, recheck the ecu. IF its chipped recheck the mapping. White smoke from throttle body, the only time I've encounter that is when i sprayed starter fluid in the throttle body to start the car and I got like a back fire and white smoke came out. Timing was off and it fixed the problem. I would recheck everything to be sure. Sometimes we overlook the smallest thing and usually that's our problem.