94 ultra no acceleration

i have a 94 ultra i just bought. i had to replace the fuel pump, the sending unit was rusting out but now i lose acceleration around 30mph it stumbles until i brake and sometimes it feels like when it kicks down my brakes pressure up real hard . but it launches like a demon. i have replaced fuel filter & pump, plugs, wire's & re-ran all vacum lines. but noticed if I turn off the traction control it runs and shifts fine no prblems at all. would that be something electrical, vacum or in the tranny? im outta ideas!?!?

any warning lights? abs,brake ,track,service engine soon

im not getting any lights. the guy i bought it from told me about to keep the tank full or it runs bad like it is running out of gas but that was the rusted out sending unit i fixed that. but even with a full tank still have this problem. but it doesnt happen all the time but if i hit a bump it will happen. but like i said if i turn the traction control off it runs fine. no problems at all. i have done all the quick fixes i can think of and dont think it would be something like a coil pack or map or iac if it doesnt happen when the traction control is off was thinking more tranny related but see alot of people had similar problems with different solutions but alot of it sounded like just replacing something untill the problem stopped.*****After reading the owners manual its doin everything as if the traction control is kicking on with the lose of acceleration, retarding the spark and braking what can i do to fix this?

i figured it out before i spent alot of unnecessary money on alot of different things. when i purchased the car there had been alot of re-running of vacuum lines. i went to the scrap yard and found a supercharged bonneville that was complete i purchased the whole vacuum system for 2 bucks and hooked it up in the parking lot and now my Ultra truly lives up to its name. there was a vacuum union that sits on top toward the back of the s/c which was old and weather cracked and the rear lines just werent there. but thanks for nothing lol. J/K hope it can help someone else with the same problem.