fuel pressure???
my fuel pump humms while giving giving gas at speed of 20-50 mph, i changed the fuel filter and the gas was black and it ran great with a lot more response for about 15 miles and then ran sluggish again and the humming came back, that was 300 miles ago. im going to change the filter again this weekend just to see how it looks and im going to check my pressure also. any idea on what the pressure is supposed to be at idle and what not? it is an 03 Cadillac cts 3.2L or where i might be able to find this information? thanks for your help