Misses and sputters

Engine Performance problem 6 cyl Two Wheel Drive Manual 80,000 miles

Hello, I have a 1987 Toyota supra with a 1989 supra 7mge engine. I just did the swap and it runs okay, it idles fine, but on acceleration it misses and sputters some between idle and 3000 rpms when I accelerate hard. And a little during normal acceleration. But after about 3000 rpms it pulls just fine. Also after hard acceleration when I press the clutch in to begin deceleration the motor will die? It does have an exhaust leak where manifold meets down pipe but I didn't figure that would make a difference. The original motor did the same thing only worse.

Well its not every time I press the clutch just sometimes and it doesn't loose all power if I keep on the gas it stays up and that problem must have worked itself out for the most part because it has only done that a couple times since last post the big problem now is the missing between idle and three thousand rpms.

any ideas.