A/C help needed!!!
 

Hey,

I got another problem on my 4runner. This time it is an AC system. I live in Los Angeles and I need a fix fast, cuz it's 110 degrees outside. Here is the problem: when I first start the truck in the morning, the AC blows cold air (even though it could be colder), but if I shut the truck down and leave sitting in the sun for 20 minutes or more, when I start it back up, the AC blows almost worm air. But when I get on a freeway it blows cold again. What could be the problem???

P.s. it's 91 4Runner, V6 auto 2wd

My mechanic said that it MIGHT be:

87240-89127 Rear heater valve

But he is not sure. I don't wanna pay $90 for the part & 150 for installation if he is not sure.

Anybody?

I'm not exactly sure how a 91 with factory A/C should work but unless the rear heater is blowing hot air all the time I wouldn't think it would have any effect on the A/C.

As far as the A/C working better on the freeway I would check to see if there is an electric fan for drawing air through the condensor (in front of the rad). If there is a fan it should activate when the compressor is running. Also check to make sure the condensor is clean.

How long does it take to get cold? If it's just a few minutes (3-5) that's probably normal in 110 degree weather.