secondaries dont have much of anything to do with this problem, since you have a 95. You dont have an IMRC box, hentz your secondaries are vaccume operated. As for them opening, they only open when you pass 4K rpm's. At which point your engine knows you need to GO GO GO so it sends your gas mileage down the drain and lets the engine push hard. THIS sounds a hell of a lot like a misfire issue, like sometime wasnt installed correctly when you were changing your plugs and wires. Do you get a CEL or any kind when the bucking occurs?
If your Secondaries werent opening or not functioning correctly, the only time you would feel it is if you ever passed 4K rpm's. Not if you just gun the throttle for a few seconds.
