Here is a trick that can be used to find the TDC of the compression stroke without a gauge. So I am working on a 3.4 swap and after doing a valve adjustment and timing belt change and it wouldn't start, I had to rule out my timing. I didn't have a vacuum/compression gauge to find TDC but I did have a condom and a piece of 5/8th inch hose.

I wanted to see if my timing marks liked up on the compression TDC so I taped the condom around the hose, "sharpened" the other end, jammed it into the #1 spark plug hole and gave it a twist. I then turned the crank and waited for the condom to get a hard on which would tell me the compression stroke.



When I found the compression stroke, I then inserted a telescopic magnet into the plug hole and rotated the crank until it was at the top of the compression stroke JUST before it went down (exhaust stroke).


My timing marks lined up at the cams and crank 0 mark. My problem is not my timing......must be electrical.

 

In place of the telescopic magnet, I recommend a plastic straw or a wooden chopstick. You started very close and were very careful, and the magnet is not TOO strong. But if one used, for instance, a long screwdriver, a mere slip of the wrist can gouge the top of the piston or screw-up the plug threads. The chopstick or plastic straw would just fold up.

 

Hell that's way easier, I always used a long hose stuffed in my ear to listen for compression.

One thing though, "just before the piston goes down" isn't the exhaust stroke, that'd be your power stroke