how can you tell if you have low refrigirant?

[youngrider]

ako naman pag a/c naka open parang hirap humatak. pinagawa ko kay mang mario yung a/c ko full cleanning pa nga pinagawa ko dun at nagpalit narin ng dryer. anu kaya prob dun.pag patay naman a/c di naman hirap.

Yan ang function ng 'Idle-up mechanism', to compensate to the increased power need when the A/C is on. Di lang eto sa idle tumutulong, it also helps in providing enough power during acceleration or increasing load first by giving a stroger base torque to begin with, and also by adjusting the spark timing.

Kumporme sa design ng car (diesel vs gas fed, computer controlled vs carburated engine, etc) kung paano ang mechanism ng idle-up or aircon cycling.

Cars with VDC especially w/ computerized engine management may not perceived power related changes (basyo, nginig, RPM hunting) when they switch on the aircon or when it cycles. Halos pareho pakiramdam naka-aircon o hindi.

Whatever the system is, the question is operational ba ang compensating mechanism (like idle-up) to accomodate the load induced by car air conditioning system.

[spyghost]

As to the erratic idling of 'spyghost' , it could be related to spark or fueling problem, vacuum leaks can also be a culprit. These could adversely affect the idle-up control of the engine as the aircon is switch-on especially with those having non Variable Displacement Compressors (VDC).

my problem is NOT the idle up. whether ac is ON or OFF, i have a 900 rpm idle which is the normal for my car. its worth mentioning narin, since i am running a carb engine, my idle up involves a vacuum solenoid that ports intake manifold vacuum to push the throttle plate whenever a/c turns on. no problem with this circuit.

what i am experiencing is i have an erratic idle whenever the a/c clutch engages. imbes na uga uga, e yanig ang nangyayari. take note that this happens even if i am running at 900 rpm. given this idle speed, the engine does not die on me.

i don't think a/f mixture and other fuel delivery circuit is concerned here since i just finished tune up with proper valve clearance, new filters, new plugs. btw, the plugs come out clean after one week of run - so it is safe to say that there are no problems in the engine.

[smirky20]

pag low na po ang freon yung A/C clutch nagpapatay sindi and yung idling up and down din sumasabay sa compressor. and pag totally wala ng pressure sa A/C sytem, d na mag e-engage ang clutch dahil wala ng contact sa pressure switch.

ang nagcocontrol naman sa idling whenever u turn your A/C on is either vacuum on old model na car and sa newer model naman yung IAC (iddle Air Control).

[groucho]

kung nababawasan ang freon then better have it fix na...since a/c system is sealed hinde pwedeng mabawasan unless meron leak na somewhere...

I have a question which is corollary to this regarding a 2000 Toyota Corolla. What if the car's airconditioning was rarely, if ever, used? What if the new owner now wants to use the aircon and finds out that it does not turn cold after all these years of practically not being used? Would it still be assumed that the freon or whatever refrigerant did not leak out?