got a 92 firebird, auto 3.1 engine

pulls fine until 2nd gear from 4800-5400 rpms, it just dogs real hard, then when it finally shifts, pulls good again,,,has a very very recent tune up. did it before tune up also.
sometimes it wont do it when the car is real cold, but rarely.
any ideas or suggestions?

-Jason

 

The 3.1 peak hp at 4400rpm that night be why.

 

but then why in 2nd gear only??, it stops pulling, then starts pulling again at like 5300 or so..

 

maybe something with the coil packs? If they're old I think they have trouble providing enough voltage at high rpm? I could be wrong...

 

You might want to do a ignition check from your coils to your plugs.
Valve spring getting old or week.
Are upi getting any detination in that rpm range?