99 sunfire

When you say upper unit, you mean the camshaft? If the camshaft is not turning then the timing can't be right as you mentioned, check for stripped or broken timing chain or sprockets, pulley might be turning but not the camshaft itself

The crankshaft and timing chain and gears are turning but no compression.

Then it's out of time or bad valves

Ok so here's what I've seen. When you turn the car over it makes a whining sound like its free spinning. The crankshaft is turning, the timing chain and gears are good and turning and the rockers in the head are all moving.