i got a 02 zts been workin on. when i bought the car it was at a junk yard it was a good price so i said hell why not...turns out the car was stolen and in process of being striped. cops busted the party and now a year or so later i got it. turns out the gas tank was sabotaged with sugar. got all that cleaned up and put back like it was. got the motor all back togather went to start the car it ran for a minute and shut off. got a new battery and some odds and in parts that i still needed. got all that on there and started it up again this time it ran for about 30sec. then died again... now the car wont start at all. it trys to start but will not turn all the way over. about the second or thrid try the car will back fire... does anyone have any ideas that might be causing this problem?