I was changing my TPS sensor in my 1990 GMC Jimmy V1500 (350 ci TBI, auto trans,...) and I broke one of the torx screws that attach it to the throttle body. I had to drill it out and I'd like to re-tap the hole and get a new screw for it. The problem is I can't figure out what size and pitch tap I need (all the tap and die sets I've looked through don't have the right size). I'm pretty sure it's a metric thread -- 0.75 seems to fit perfectly, but I'm not sure what size to get. It appears to be about 5mm or 4.5mm in diameter. I found a place (mail order) that sells metric taps for a reasonable price, but I have to provide them the correct size. I called my local dealer parts dept. and they don't have the size listed in their computer. Does anyone know what size I need?