Hesitating Holley

[69L89396]

From my experance, you have to make sure there is NO play in the acc. pump arm. Just make sure that the pump arm moves as soon as the throttle arm moves. I have tried the acc. pump arm gap set at .0010" and have not had any luck. If you get it too tight, you won't get a full pump but that usally doesn't effect anything. Most of the time it is just a little too much slack.
If you don't find any slack, check the plunger under the nozzle. It might be letting the fuel drain back to the pump a little. If this is the case, when the pump starts to move, it just pumps air.
What is happening is the vaccum is dropping when you first open the throttle and the pump shot covers up the dwell time until the vaccum picks back up. I hope I explained this right.
Good luck