Car hesitates/bogs down, help plz

[S13Koop]

Car:91 240 w/ SR20DET(redtop) stock except for Blitz BOV

Today i noticed when I floor it the car hesitates then just totally bogs down. I thought for a second I left the e-brake on.
It only does it when the car is in gear, in neutral it revs up fine.
Also when I floor it the car jerks pretty bad but if I gradually accelerate, it seems fine with no jerks.
I'm going to check my wiring and for vacuum leaks.

Could it possibly be my clutch slipping? I've never had a clutch go out on me so I wouldn't know if its slipping or not.

tia
-will

[jtt220]

I am experiencing the same problem. She runs good when sitting in the driveway (revs freely and smoothly), but when I drive it hesitates and blows smoke badly. It is not the clutch, I think it might be some bad valve seals. Either that or improper Air fuel ratio. I really don't know either. What setup are you running (engine, car, harness, distributer, ecu, upgrades, ect..)?

[S13Koop]

Car:91 240 w/ SR20DET(redtop) stock except for Blitz BOV
no other mods whatsoever