What up everyone!

Ive got a 91 Integra LS and it is running like crap.

When driving the car and the RPMs are under 4500 to 5000 the car just runs real sluggish and has no power.

When it hits 4,500 to 5,000 rpm its like the darn thing has vtec, motor runs smoothly and it takes off with some serious power.

I have replaced the plugs, plug wires, d-cap and rotor, fuel filter.
I have ran injector cleaner through it too and nothing seems to help..

I mean the car is lacking serious power until you get above 4,500 to 5,000 rpms, from 5,000 to 6,800 the car has some serious get up and GO!

Also, when the car is cold, after sitting all night, when i first start it up, it wont idle.. The motor jumps around from 700 rpm to about 2000rpms, I have to hold my foot on the gas to keep it from dying..

Any ideas what could be causing this problem?

Any help would be greatly appreciated.

Thanks,

~Matt