diablo

I have an 89 pickup with a 22rec. Has anyone had this happen, it idles fine (smooth) makes good power but above 2000rpm when Im under the hood it misses a little and continues to do so until around 3200 rpm. I have replaced the TPS adjusted the valves. I do not believe it misses under load (driving) as I have good power on hills and all around. Anybody with info would be great. I get no trouble codes @ all...........