I need a little help. 1999 chevy 5.3 v-8 motor in 1957 pickup. Computer controlled. No engine codes have alerted. Hessitates as you push down the trottle (cable throttle), but only when cold. warms up, goes away. Happens under engine load, not in neutral. Haven't changed fuel pump or filter because it's not a constant problem. Only on a cold startup. Any ideas.
