So on top of the issues i already had with the car not wanting to rev past 4500rpm and somewhat bad mileage(23-25mpg), the car has recently developed a bad sputter/hesitation under normal driving conditions. the idle has also dropped 1-200rpm from normal and i've lost a couple mpgs

It feels almost like an extremely bad vaccum leak or like i'm running on 3 cylinders, but if i drive the **** out of it and manage to keep it between 3-4k for a while it will clear out a bit and run normal. Any thoughts?

for referance, its an 88 civic 5spd d15 dpfi. Thanks.

 

check the usaul like plugs,wires,cap and rotor or just swap to mpfi.