Got my Olds minivan back from the dealer for stuff not related to the engine or fuel. Filled it up and about 10 miles later it was bucking like a PBR bull. I figured it must be water in the gas. A bottle of Heet didn't help at all. I'm now on my 5th tank after it started. I changed the fuel filter and ran the tank down really low before filling each time. It's still doing it. Not as often but just as bad when it does. Every tank has been from a different station so the likelyhood of bad gas at every station is pretty slim. I'm beginning to think ignition not bad gas. Any ideas?