Check to see if these wires have 12 volts at the mass air flow sensor using a multimeter. This voltage will only be applied for approximately 5 to 30 seconds after the engine has been shut off ...

He decided to replace this with a modern mass air flow (MAF) sensor instead, and documented the process online.

This sensor type is based on the principle that if a mass is maintained at a constant temperature (above ambient air temp), the thermal loss is proportional to the flow of air over that mass.