97 KA24DE in 95 body...problem.

[Been.Boostin]

Long story short...i have a 97 KA24DE in a 95 body. The car has trouble starting, drives fine however untill i floor it (while driving obviously) it sputters and the cars starts dropping in RPM's and slows down..as i let off the gas it bucks..then it will go back to driving normal..untill i floor it again.............Right now the car has the stock 95 wiring harness on it...and there is a green connector exposed(near the top of the intake manifold) that's not connected to the harness(because on the harness there is no connector for it) ..right above the fuel lines(near the intake manifold).....i'm trying to figure out a few things....could this bucking be due to this plug not being plugged in...or could it be a fuel pump or what??? Any suggestions...i've changed spark plugs..and there are no vaccum leaks..