1986 Nissan Pick Up Problem

[DAN 1]

My 1986 Nissan Pick Up "chokes off" when I press the accelerator past the half way mark. It clears up when I lift up on the accelerator. So far have replaced the distributor cap and the fuel filter. No improvement.

Any advice about this?

[Rev_D21]

4 or 6 cylinder? Sounds like it could have a vacuum leak or two.

[DAN 1]

Howdy Rev-D21. Its the "2.4" engine with four cylinders and two spark plugs per cylinder. I'll carefully check the vacuum system. Thanks.