I'm close to buying a 1991 firebird, 305 TBI. Everything is great except when you raunch on it. It idles great, revs in gear like nothing is wrong. You put it in drive, and take off, it does fine except for a small small miss. When you lay in to it (1/2 to WOT) it pops, backfires and hesitates. Car was at operating temperatures when I test drove it so I am not sure if it acts any different when its cold. It's almost like the timing changes between city mode to whoop *** mode. Any thoughts?