Backfiring usually is caused by too much initial advance.............
i have a 1988 corvette with the L98 motor and i have and idle problem and sometimes it will backfire once or twice while sucking in air and this will only happen when the motor is cold but once the temp hits 160 degrees the idle gets better as well as performace. i don't know if it's the new computer chip and that i should put in the old one or if its something else that i am missing. any help would be great