Stuttering when barely hitting gas

I have fixed everything on this 93 corsica i got and it runs great, but when i try to maintain speed and am barely pressing on the gas it will jerk, but runs great if i let off the gas or press harder and start accelerating. its a 93 corsica with a 3.1L 6Cyl Engine. I have replaced the throttle position sensor and the fuel filter. what could be causing this? I figure if it were the fuel injectors it would happen idle or accelerting.... any ideas?
TIA

I just had a friend say it could be an automatic transmisison issue, but I dont really know what aside from a tranny problem could cause this and how it can be fixed, and im broke so taking it to a shop is out of the question for now, aside from changing the fluid. what could i do on my own?

is it a 3 speed with lock up or 4 speed? if its a 3 speed try to unplug the plug in the front of the trans then drive ,if the problem goes away its in the tcc switch if its a 4 speed try this when the problem happens try putting your foot on the brake ( very lite )see the problem goes away.tryeather one of these

Well. its an automatic.. and I have noticed the engine moves quite a bit when i shift, maybe a broken mount? i have tried to see for myself but im fairly new to working on cars and cant find them.. is there a diagram somewhere that would show me?

I had the same problem.

It was a broken rocker arm stud.

A trip to the junk yard yielded a used one and that cured it for about a week!

Then the same rocker arm came loose,yes I torqued it.

Torqueing again solved the problem,I hope.

its been 2 weeks now.

Take a cylinder compression chek.

The bad stud or rocker arm will show,as that cylinder will have absolutely NO compression.

Another clue would be that it des not idle smoothly.

A lot of Chevy rocker arm nuts are lock nuts. If it comes loose again use a new lock nut. If the stud is coming loose use lock tight.

I just had another stud break.

Are these a prob with the 1994 Corsica?

I replaced it but am worried another one will break.

That`s 3 so far.

Should I replace all the rest?

I also have one cylinder,naturally in the back,where the tappet is noisy.

Its not a loose rocker arm as I checked it when I took it apart yesterday.

That leaves either a lifter,bent pushrod,or,(here it comes!),the cam`s rounded out.