02 Jetta TDI - won't start

I replaced my 02 Jetta TDI engine with an engine that had 49,000 miles on it and have driven the car about 250 miles since replacing. All went good with the engine swap, replaced timing belt / water pump before installing.
This morning I parked the car and shut it off, went into a store and came back out it would not start!!
Replaced fuel filter and verified that timing belt was still intact.

Any ideas?

Thank you.

check your glow plugs