95 olds 88 Royale - Power problems(car keeps dying)/rough acceleration

I have a 95 oldsmobile 88 royal 3800 series non super charge. Car was working great when i was living in Georgia but recently moved back to ohio and drove it the whole way there with no problems. After 2 weeks of being back at home my upper intake manifold failed which caused antifreeze to get into my oil so i had my intake manifold replaced but when i got it back from the shop i suddenly had another unexpected problem but only when i first accelerate it kinda hesitates while picking up speed very slow an depending on how hard u mash the gas it can give a few jerks so u have to slightly press the gas but after i reach speeds of atleast 15mph the car rides like normal no problems only when i 1st accelerate. Now the shop said they believe its the transmission but i dont think its that bc i havent had problems what so ever before my intake replacement. The funny thing about this problem is when i start my car and lets say i take right off after a few seconds the car is fine shifts perfect rides perfect but then after a few mins of driving and a few stops all of my lights and the dashboard starts to flicker from dim to normal constantly and from then on the problem starts but only after it starts the flickering but car was still drivable. After a week or 2 now another problem developes my battery wont stay charged so i took my alternator to get checked and it test fine so i grabbed a fresh battery just in case and it still wont stay chared so i have to get a jump just to stay alive... This car is driving me crazy but only after i had my upper intake manifold replaced. Someone plz help me out????

Check all the engine and battery grounds for starters.

Check all the engine and battery grounds for starters.


I will do so first thing in the morning with my personal mechanic... but does this sound like something familiar you heard about before and does it really sound like my transmission is the problem cuz it never slips or misses a shift

Poor grounds can cause any number of issues both with eng and trans performance.