Is it normal for our cars to drop almost 500RPM when the AC button is turned on? I have an '87 Auto Maxima. I have the idle set perfectly, but when I turn the AC on if I am idling, the car will die in about a minute and runs very very rough. 500RPM seems like a high drop to me, just wondering if that is actually normal. Thanks.

 

Your RPMs shouldn't drop when the AC is on. They should rise. You might have a problem with the AC system.

 

Actually they won't neccessarily rise. The FICD will bump the idle up when you turn on the cabin fan, but if your A/C system is properly charged, it may drop slightly from where the idle was when it was bumped up because of the load it will put on the system. In your case though, for it to drop to 500rpm, then stall, I wonder if there is something up with the compressor, OR the FICD may not be functioning right, and not bumping idle up a tad before the compressor kicks in.

S

 

I have the same problem...I am still trying to figure out what is up with mine as well. Mine does not stall but it will drop down 500 RPM...let me know if you figure out anything and I will do the same. Mine does it on a 5 speed so I guess we can rule out something having to do with a specific transmission.

 

I wonder if you guys are having some sort of compressor problem? It could be that they maybe bet seizing or something. How is the A/C system working? Also have you check the sight glass for any anomilies?

S

 

I am not sure if that is the problem with mine....my AC works fine and it is nice and cold...and when I look in the site glass I can see freon/AC stuff...who knows

 

hmmm, with the car off, you can try turning the little clutch and see how freely the compressor turns?

S

 

Well I haven't had a chance to check it yet, but the AC works fine as far as cooling goes. I have actually gotten cold on 95degree days. Also just to note that when I turn the fan on without the AC, the RPMs do not drop at all, it is only when the AC is switched on. And how would I be able to check if the compressor turns freely in an Auto trans? Thanks for your comments on the issue btw.

 

Well I think I have solved the problem, for my case atleast. Seems it was the Air Regulator surprisingly. My car was would go into hot mode very quickly when the ignition turned on and has done this for a long time. I decided since I was in a fix it mood, that I would try doing that Air Regulator fix posted in the sticky on the forum. It fixed my bad start-up problem and fixed the A/C problem. Now the A/C only drops the RPM's about 30-40RPM which is well within my standards and does not make the car rough idle when turned on. Just wanted to let you guys know and hopefully that is cardana24's problem also. Much rather do a simple repair than have something wrong with my compressor Thanks for your comments.

 

hmmmm....I doubt that is my problem but I guess it could be...the reason I doubt it is because my AAV is only about 6 months old?

 

Well it really only took me about an hour to do the whole repair, so if you have any doubts, I doubt doing the repair will ruin the Air Regulator, but don't take my word for it. But from what I read, the Air Regulator seems to be a very common problem on these cars and goes back often. So possibly even 6 months is enough time for one to die?

 

I still have my old one so the repair could not hurt that one...did you just use the write up in the stickies?

 

Yep I did the drilll a hole in the neck and insert a screw method that someone posted on CarDomain (link in the sticky.)