you need to fit that shield, nothing I did would stop this from happening on my 1.6 till i put the shield on! A couple big jubilee clips round the shield & mainifold will hold it on if all the bolts are knackered.
ids that pic of your actual airbox? if so thats never going to work as it needs to be a sealed unit to draw nothing but warm air. There should be a vac nipple on the carb somewhere which runs to the air temp sensor on the bottom of the airbox, then there is another pipe to the nipple in your picture.