My dad's 94 V-6 is having some problems. It smokes, kind of blueish in color. It smells like gasoline. It also misfires and bucks while driving. He just got done changing the head gaskets and put on rebuilt cylinder heads, but it didn't fix the problem. Anyone know what could cause this? I posted this in the V-6 forums here but figured someone here might know whats going on. Thanks a lot.