Refuel Dig to bedrock then up [fuel, chest, block]

turtle.refuel(1)

if turtle.getItemCount(2)==0 then
    placeChest=false
else
    placeChest=true
end
turtle.select(3)
turtle.digDown()
turtle.down()
turtle.digDown()
turtle.down()
turtle.placeUp()

while true do
    if turtle.down()==true then
        turtle.down()
    end

    if turtle.digDown()==true then
        turtle.digDown()
        turtle.dig()
        turtle.turnLeft()
        turtle.dig()
        turtle.turnLeft()
        turtle.dig()
        turtle.turnLeft()
        turtle.dig()
    end

    if (turtle.digDown()==false and turtle.down()==false) then
        while turtle.compareUp()==false do
            if turtle.up()==false then
                turtle.digUp()
                turtle.up()
            else
                turtle.up()
            end
            complete=true
        end
    end

    if complete==true then
        turtle.digUp()
        turtle.up()
        turtle.up()
        if placeChest==true then
            turtle.select(2)
        else
            turtle.select(3)
        end
        turtle.placeDown()
        if placeChest==true then
            turtle.select(3)
            turtle.dig()
            turtle.place()
            times=3
            while times <= 16 do
                turtle.select(times)
                turtle.drop()
                times = times+1
            end
        end
        return
    end
end