Welcome to FJ!!
If it sounds like the starter is spinning too fast, or 'not doing any work' kinda thing, I'd suspect timing belt.
Pop out a plug and see if there is pressure in the cylinders (disconnect coil pack wiring first to be safe).
Other than that, it could be many things. I'm going to point you to the sticky
HERE. And try to give us more info. Were there any problems the last time it ran? Any Check engine light? Anything that might be a pointer?