I have a 1990 4runner w/ 3VZE. i have noticed that my coolant temp gauge takes a REALLY long time to come up to operating temp (close to 10 min doing 80 km/h) although i am blowing hot air within a few min. I think its impacting my MPG. Wondering if anyone else may have had this problem?

 

Either the thermostat failed open or someone took it out. When did it start doing this?

 

Ever since I got the truck 3 years ago.

 

I would start by installing a Toyota thermostat. I got one for about $20-25 at the dealership a few months back.