Have you had it running in hot weather before, sounds a bit like the fuel is boiling off, might try a carb spacer. Edit* I see it's injected, possibly the temp sensor for the ecu is no good

Also you might check the flow of the fuel pump, I have had a mechanical pump fill up with crap from the tank and could idle and low speed ok but anything more than walking pace would lean out and die. Have also had an electric pump wear out and would be fine till I got on the open road and put my foot down