I put on some Curvy Girl valve stems so I could use some tpms valve caps with my GPS. I went to check my tire pressure this morning and I am getting some strange things. First, depending on the direction my gauge is pointed, I get very different readings. One way maxes out the gauge at over 50 PSI, the other way I get around 35. If I try to add air, I don't hear any air going into the tire. Has anyone had problems like this? Gauge is a regular stick type, but I am puzzled that I cannot add air.