Replace the t-stat. When I first got my 89 with a 22re a few months ago I found the radiator was leaking. I replaced the radiator & bought a t-stat from Napa back in 10-07. The water pump went out the follwing month so I changed it but didn't do the t-stat since it was new. The engine would do the same thing your is doing so I checked for a blown head gasket & it was ok but would still get to the red for about a minute & cool down after the t-stat opened. I decided to change the t-stat again but this time I bought it from another parts store. Now the temp gets upto about 1/4 & stays, problem solved.
