Been fighting this one for a few years but seems like something quit on me. The A/C idle up doesn't work anymore. No vacuum leaks, I've checked it several times. That leads me to think some part has failed.

I have little experience on these and the FSM has some tests to try but wondering if there's a specific part I should be focusing on. I'm thinking it might be the VSV if I'm understanding the system correctly, but could it also the the actuator? Any direction is appreciated, it's getting hot here in California!

 

Did you run the tests? What results? They don't write these Manuals for the fun of it.

If the tests pass, I'd start with assuring that you actually HAVE vacuum on both lines. If the plenum (upper intake manifold) fills up with "gunk," it can clog either port. no vacuum, no idle up. (It happened to me.)

Then test each component in the "circuit" to isolate the problem. Bypass the VSV (hook the two vacuum lines together) to see if the actuator actually causes the idle to rise. Put 12v right on the VSV to see if the valve opens. It shouldn't take too long.

 

Ok Now I understand AC quits time for a new truck

 

Haha! No, not entirely. I've got front end vibration in the drive line, a valve knock that's getting worse and intermittent codes 25&26... it's dying a slow death.


I didn't think about clogged hoses... that's a good thing to check as well. I did some plenum cleaning about 6 months ago and it's possible the line was clogged.

 

Just to follow-up (mainly for the archives for the next person who searches):

Looked at it over the weekend and found no issues. Hoses are fine, wires are fine, A/C works now. Seems like it might have been since the idle dropped a bit lower in the 105+ heat and combined with my hyper-sensitive IAT sensor in the Supra VAFM, that might have been it.

On the upside, I learned how to adjust my A/C idle speed!

P.S. Amsoil Powerfoam ruins your O2 sensor But I had a spare anyway and knew that going in.