Suze, the Walbro you got came off of ebay from what I just read (it's late here and I'm tired, so I may have misread).
I wouldn't trust a Walbro from ebay, they are damn near impossible to tell the difference from when you have the real deal sitting right next to it. The are engraved the same, same shape, same color conectors, EVERYTHING.
I don't really know what to tell you other than, try a different pump, one you know is real, like purchasing from a reputable seller, or just keep an eye on your AFR's like someone mentioned earlier.
