There should not be any lag at all. Try resetting the throttle by turning the key to power everything up but not turning the engine over. Press the throttle down the whole way for 5 seconds or so. Release it and them turn key totally off. Go for a drive and see if it made any difference. If not, there is something else wrong. Possibly the HE pump or maybe someone else has another idea. There should be instant throttle response at just about any speed. Not sure about the washer fluid.

Steve