Toyota Repair: 92 Camry 2.2L - Apparent Timing Problem, crank pulley, tensioner pulley

Question
165k miles on car...supposedly 50k on engine installed Dec 2006. 3/2008, sudden onset of hesitation, then rough running, missing, whether at idle or driving...esp. when warmed up.  All indications are timing problem per mechanics. I installed a new belt prior to problem...could have used wrong mark to align the Cam gear...a notch or two.  Compression tests reveal all 4 cylinders LOW!!! 53 to 69 psi dry, 89 to 114 with oil.  Could this indicate worn rings and ALSO timing belt alignment problem?  Can I adjust timing belt by just opening the top T-Belt Cover with crank on 0 degrees TDC & loosing the tensioner?
Any suggestions most appreciated, Phil

Answer
This does seem like the engine cam timing is off, to check it just remove the top part of the timing cover, remove the spark plugs, rotate the engine to the 0 mark on the crank pulley and make sure the number one piston is up,there is a hole in the cam gear that should line up with a mark on the top of the front cam gear housing, use a mirror to do this. Make sure that all of the timing belt slack is taken up between the bottom pulley and the cam gear before releasing the tensioner pulley, the tenwsioner should take out all the slack in the belt, if the belt is not tight enough the timing will jump, good luck with this and let me know if I can answer any more questions for you.