93 3.1 troubleshoot

I own a 93 with a 3.1. The car has a miss and backfires when accelerating. If you accelerate up to about 3000 rpm the car will smooth out and run great. I have replaced the coil packs, the mount bar they are on, plugs and wires and still have not resolved the problem. Anyone have any ideas?

surely there is a SES light if it is missfiring. whats the code?

just the clarfiy. the miss is below 3K, after 3k its fine. whats the mileage? double check the arrangement of the plugs from coil to cylinder