Originally Posted by c1apton
check ALL your vac lines for cracks (including Bellows tube) also try cleaning your MAF sensor. It could also be signs of a fuel pump going bad - they do get weak w/age. And believe it or not the seal on your gas cap can cause the symptoms you described.
Had similar happen to me a few years ago, turned out to be the breather hole in the fuel cap was blocked causing a vacuum in the fuel tank, fuel was struggling to get through to the engine.