pump has multiple speeds, there is somewhat of a surge when speeds change. Until this hits the FPR and it adjusts, there could be fluctuations in the fuel pressure causing variation in fuel mixture. This may happen too fast for a wideband to pickup with up to 360 combustions per second. If you are lean there could be problems. I guess a lean condition would probably be when the pump goes to a slower speed, and the engine would generally be stressed less under this condtion. The damper probably helps in throttle response by keeping the mixture from getting too rich when the pump changes to a faster speed. I know some run without a damper, but how do they justify this?
