E C K S J A Y

I have a 1999 XJ sport, fully stock with 215k miles. This issue is very perplexing and I've had no luck so far even after asking my mechanic friends.
The plugs, wires and distributor cap have been replaced very recently, along with the fuel pump and even the torque convertor. The engine has 100% full power in reverse only. I can tow a full size truck uphill in 4HI going backwards with no issue whatsoever. BUT when I try to accelerate, especially from a standstill, moving forward is extremely jerky and I have stay below 1500 rpm or it will cut out and buck like a bull. Has anyone encountered this exact issue before?