1987 Nissan Stanza help

Do whatever is necessary to seal that tube. All air going into the engine has to go through the mass air flow sensor to be measured for proper fuel metering. Even a small leak can cause a hesitation, stumble, or hard starting.

Check the salvage yards for a replacement tube. If you're anywhere between Ohio and southern Georgia, there is a real nice chain of yards called "Pull-a-Part". You can do an internet search of their inventory to see which yards have cars like yours.