I have a 2001 chevy tahoe wont start

i have a 2001 chevy tahoe with 176,000 miles, i was driving the other day as usual and all of a sudden my truck bogged out (died) as if i was out of gas. i spent an hour trying to start it and then finally was able to catch an idle barley getting me accross the street (bogging) to a gas station. i had planty of gas, oil was just above add indicator 2nd circle above add, i took battery to get checked and read it was completly dead, changed it out and still nothing, every once in awhile since then i attempt to start truck and sometimes able catch a quick start low idle boggs out and dies. battery volts shows just above 9 when key is in even with new battery that i got after the other one was said to be dead, i do remember before all of this battery was in the middle now not more towards 9 please help