Replaced Timing Belt

I replaced the timing belt and water pump on my 97 honda passport 136,000 mi. I made every effort that all timing marks lined up in their correct postions.
I used plastic clamps to hold the belt secure and rechecked timing marks numerous times during rebuild.

The problem is the vehicle is sluggish lacks power and idles a little slow.
Does anyone have any ideas of things I could check before I start tearing the truck down to the timing belt again?

Barry