I had the same problem. It was difficult to actually see, but the air cleaner housing was hitting the plate on top of the valve cover that holds the 3/2 valve and some of the accelerator linkages. I took a 2 inch piece of heater hose, split it longitudinally, and placed it between the filter housing and metal plate. It would fall off every few days until I punched a hole in the hose and secured it with one of the bolts that holds the plate to the valve cover.