Well first check the connector to the pump for burnt/melted condition IF pump is not running! Check fuel pressure make sure it not another problem like VAT (theft) system No dont just run out and buy parts until problem is properly diagnosed!! All we can do is suggest certain possible causes.However if pump replacement is required buy a good unit.
ok thanks for all your imformation i appreciate it i checked the presure and it had 30 one time and 10 another it throws the tighten gas cap code evry now and then with this pump thats in there now it will idle but real ruff and just for a little bit i tapped on the tank for a bit an had my son give it some gas and it ran just fine as long as i was tapping on it
I say the pump is your trouble but check the harness connector inside to see if any sign of heat which is caused by high resistance which is caused by poor connection. Dont have to purchase pump from GM but get a quality part! New connector should come with pump module.