94 s10 blazer 4.3 vortec vin W

My truck starts up and runs like a top. the next day i go to start it and it will ( buck) when it starts it will idle fine but if you touch the throttle it will run very rough, i have no check engine lights lighting up, i took it to the local garage and 11 days later they say their is no problem with it.
i drove it home ( ran very good ) the next day it acted like the battery was week and it bucked again, idle is great but will not run when i give it gas, PLEASE help me with this 4 month old problem.. jim

what all have you done so far? tune up, including fuel filter? pcv? check fuel pressure and vacuum hoses.

all basic tune up, plugs, wires, cap, new gas tank it was leaking, the problem started about a month after the new tank was installed, also cleaned the egr valve.

check the connections to the pump. did you change the filtert?

Just for giggles, run your nose along the driver's side frame rail from the fuel filter to the tank... Sniff for gas...The reason I say that is on our trucks the lines tend to corrode and when you change the tank they develop pin hole leaks... Just a thought...

Found no gas leaks, i changed the fuel filter and the local garage said the pump is puting out the correct pressure but it never acted up for them.
i even filled the gas tank up completely, checked all connections to all sensors and checked all fuses. did not find any vacuum lines unhooked or rotten. i do not have any smells like rotton eggs or flooding out.
could it be a bad ground wire for the fuel pump? or how about the coil? will either of these things cause it to cut out and shake ( buck ) realy bad only under exceleration? thanks all

check your connections to the pump including the ground. you can get coil tested free at most parts stores. if you hold pedal to floor and then back off slowly, does it pick up speed while slowly letting off? if so check into getting a knew tps(throttle positioning senser).

can anyone else give me some helpful hints??? thank you all