Bucking at low RPMs, gears 1-4

[19Eclipse90]

Okay I don't really know what's up. The car barely gets going in first gear. I would rev it to about 2500 and let off the clutch slowly. The RPMs would dive down to 1000 or less and the car would barely start rolling. It would do this for about 100 feet and then it would start bucking back and forth back and forth like it was trying to go but was being pulled back by something. When I shift to second, it's fine until I push the gas pedal, and then it has the same symptoms as in first gear, and then the same stuff through 4th gear. I actually think it might have been doing it in 5th gear as well. I got on one street and tried to see if it was just at low RPMs, kept it in 2nd, and all the way up to 6500 it was bucking. I got it home, and I'm waiting for it to cool off so I can perform a compression test on all cylinders. It seems like similar symptoms that happened last time something went wrong. Oh, I rolled it into the garage and had it in nuetral, I revved it from the engine bay and the thing shakes and bucks and looks like it's about to die. Car does have 183.5K miles on it, but major repairs were just done in October, and we have continued making repairs since. So what do you all think? Valves? Head Gasket? Pistons? I'm really hoping it's not any of those, because if it is, forget it, I'll drive something else and buy a new engine over the summer.

Edit: Can't say I correctly fixed/diagnosed this one, either. The engine, transmission, harness, and ECU were all swapped after a couple years for those from a '91 turbo.

 

[19Eclipse90]

Edit:: Not only at low RPMs.
2nd gear barely engages
Car drives around fine after cooled down a bit, but acts up again after it warms up
Gasoline gauge plummets after driving around. Began the day with a little over a quarter of a tank, now have barely over empty, and I have only driven 30 miles which should have been at tops 2 gallons and gauge should be right below a quarter.

So maybe fuel line? Injectors? Bucks a lot more when you try to give it some gas. Anything guys will help.
Thanks

 

[TargeT]

how recently have you changed your plugs/wires out?

I'd give that a shot first,, sometimes its just that simple (especialy if your a turbo car)

 

[19Eclipse90]

Changed plugs about 6 months ago, changed wires a couple weeks ago. I am N/T. I changed the fuel filter to see if that does anything. We'll see.