That means you have no coolant in your overflow bottle(big plastic container above your intercooler).
Fill it up, replace your rad cap. A faulty rad cap can cause this or if the worst is true... a blown head gasket.
check your oil to see if it looks like milkshake. does your exhaust blow white smoke? does your car over heat?
probobly just a rad cap though.
edit: Just saw you're an 86, N/A right?. Doubt you have a bhg, but it could happen.