[blue4X4]

I agree, fuel pump. I just replaced mine, as it was acting very simular, with a Delphi Brand from O'reiley's. Delphi is what GM uses. Was about $50.00, replace filter when you change pump. Took me about two hours to drop the tank and replace it. Gm wanted $320.00 to do it and there pumps are $80.00. I put an off brand pump in just 6 months ago, so get the Delphi pump the first time. Good luck!