Mass air flow sensor if has one, gas engines have and do need replacing if etherized! When my gas work vans needed a shot, i drilled a small hole just past the sensor, it started & i saved $250.00!:)

Any electronic parts spray cleaner will work too :)

Why did those vans need snort anyway?

Back in the 80s the first generation of electronically controlled Detroits (DDEC-I) were absolutely horrible to start in cold weather. And if they had air starters the the headaches quickly multiplied. A LOT of ether was used that first winter and I witnessed a few engines momentarily "run away" on ether. After that ether was an emergency only item for me.