1990 300ZX N/A Sluggish throttle!

[vape-one]

My N/A has not ran for like 3years because the PTU was busted by something,, also the previous owner cut the wiring harness buckles to shreds, I have been taking parts off my older Z, Same make an model,--- My question is my Z has driver side bank running rich,, Almost like its not firing on one cylinder,, its not missing tho, Engine idols smooth... BUT WHEN I TEST DRIVE AN TAKE IT DOWN THE STREET IT HAS NO POWER OR THROTTLE ... I can floor it in first gear an maybe go 20 mph if im lucky.. Do you think it is fuel or spark,,?? Sluggish Z!!