And that is the reason I never opted for a cheap vacuum pump to feed the expensive injected pump. I was willing to carry my extra gallon in a rotopax.
Sorry I can not help you but chances are your vacuum line has fallen off or been pinched someplace. Also remember that a motor creates its highest vacuum at idle so under wide open throttle where you need the most gas the pump is being starved of its vacuum to keep it running. I know they work for others but not going on my bike.
2009 WR250R "Da Mini Bike"
"That's our colour: mud!"