Higher idling when a/c is on

[ben1988]

Hi everyone.
I noticed when I turn on the air conditioning on my 1990 camry, the engine idles on a higher rpm, probably around 1200/min. When I stop at red lights it revs on this higher level, then about 30-40 seconds later the idling becomes normal. It doesn't happen when the a/c is off. Check engine light doesn't come on, however I guess this not normal, and it stresses the automatic transmission. I don't use a/c in winter, but I'm curious what's causing this. I'm new to this car (bought it 2 days ago), what should I check?

Thanks in advance for any help or suggestions (and sorry for my English)!

[MR2Jedi]

Thats normal.

[ben1988]

Thanks, good to know.

[white90dx]

First, I'm going to assume you have a 4-cylinder car...

The increase in idle is normal - but the amount is not, especially in gear. It is easily adjustable with a screwdriver on the odd looking thing on the left side of the intake manifold. It has a spring and a bolt/knob looking thing that can rotate. Turn it down so in park it revs up to around 900rpm, and there is just a slight increase while in gear.

The idle going back down to normal is the compressor turning back off... if you wait long enough, it will turn back on.

-Charlie

[ben1988]

Hi, thanks for your help, I did what you suggested and it worked, the idling is back to normal with a/c on. The engine is indeed a 4-cylinder.