Xterra will not start after replacement of valve stem seals.

You didn't actually have to remove the timing belt did you?

I did because the compressor lost pressure on one of the valves and it fell into the head. I took the head off (passenger side) to get the valve out and did the driver side before replacing the passenger side head. I'm thinking something went wrong in that process.

There are two TDC positions. One is compression and the other is exhaust. You want TDC compression stroke.

Hmmm. Sorry to hear that. Forgive me if this is too elementary of a question, but how exactly did you find TDC? I only ask because (as you probably know) you have a 50% chance of hitting TDC using the timing mark on the crank. Sometimes people just line up the mark, and it's the exact opposite of TDC. Do you have a compression tester?

I found TDC with a straw. Took out the #1 plug, put in straw, turn crank keeping an eye on the straw, when straw comes up and starts to go back down back it up a little to get straw at the top of the stroke. I have a compression tester but I thought the motor had to be running for it to work. I am not a mechanic just a poor hillbilly with youtube. :)

I have it running, now it is just smoking. I need to figure out why. Thanks for the help.