NEED HELP, please.

[KwayKer]

My uncle and I just installed my new upper timing chain, and my ASP pulley, and a new 02 sensor. Everything went in fine and I thought things were good except for when I accelerate. Slow acceleration is fine. However, when I give it substantial gas, it hesitates, and doesnt accelerate at all. Also, going up fairly steep hills makes my car slow down, even when I give it more gas, until it downshifts (auto). It is very noticable, although the car is very drivable. The idle is fairly smooth, so we have no idea what is wrong. Any thoughts? Its a 1991 auto 240SX.

[KwayKer]

Thanks, do you have any clue how I could tell if it was a vacum (sp.?) leak? Also, does anyone else have any ideas? Help me out!

[AunVoh]

check your timing, if it wasn't doing it before and now it is, it's something you did wrong.