help with my KA-DE

[OnDaGround]

hey, i have a 93 240sx with a dohc KA. 2.5-3in. cat back exhaust.was on there when i got it..:/

problem is when i try to floor my car it feels like the e-brake is up or something.

-it starts around when i hit 4k rpm.

-revs fine in neutral.

-i know rings are bad, compression test all between 145-155
it went up a little when i added oil.(is this it right here or could it be something else causing that?)

-no smoke coming out of exhaust

-does backfire when using motor to help decel

thanks, in advance!

[Promise Land]

I would guess fuel. Maybe a clogged filter or clogged enough to restrict fuel at that rpm and above?

[OnDaGround]

ah, ok.

A friend told me could be fuel cutting.
i have replaced pump and filter still does it.
someone else told me could be a o2 sensor, buying cleaner today.
or im thinking maybe fuel line is crappy.