My blazer wont do cold starts...we had the battery checked they say its fine(not so sure) but it will turn over 20-30 times without killing the battery completely...we changed the plugs and rotor... cold start fuel pressure is 48-52 but here's the weird part, if we hook up the jumper cables the pressure goes up immediately to 60 and it starts right up! the fuel pump is only a year old tho and turns on just fine. after the blazer is running for awhile it will start up just fine the rest of the day unless it sits for more than 6 hours or so? its the 4.3 4x4 4door trailblazer package. Please help with any suggestions....thanks so much ~ Lolly