Monday, February 26, 2007 - 01:09 pm, by: Damian Ware(Frozenpod)
First of all I did a search and I didn't find what I was looking for.
My car was regassed after import, lasted 3 months then the air coming out was no longer cold, I got no error codes and no blinking air con button so I figure the guys that did it the first time did a crap job as it was arrange by the importer at the time of sale.
I took it to B&N in blackburn and they regassed the system added dye checked for leaks ect and said they didn't find any leaks and away I went with cold aircon. Lasted another 2 months now no aircon again.
One thing I have noticed is in every car I have ever driven the A/C compressor cuts in and out but in my car it runs all the time. I have been thinking about it and it should cut out when the pressure gets to a certain level and come back on when it becomes too low.
I ran more diagnostics and again no error codes.
My first thoughts is if the pressure regulator is faulty and not telling the compressor to shut off the pressure would build up and when accelerating the pressure would become too high and possibly leak out from the seals. At least this is a possible explination as to a slow leak due to over pressure. Both times the A/C failed it was on very hot days where I had the air con running flat out for extended periods, it seemed to not be working so well and the next day it was no longer cold at all.
So wouldn't B&N picked up on the pressure regulator when the regassed it. Would it be simple to increase the pressure when regasing and see the compressor shut off and again at low pressure see when the compressor comes back on. If the pressure regulator is faulty would I get an error code or would I only get a error code if the pressure regulator found the gas pressure to be too low.
Is there anyway to check/replace the pressure regulator without regasing the system ie plug in a alternate unit and see if it detects low gas pressure.
Monday, February 26, 2007 - 05:07 pm, by: Damian Ware(Frozenpod)
I haven't had a chance to take it back to check for leaks but as they didnt' find any the first time when the pressure was higher with dye. Perhaps the leak has become worse and it will be identifiable now certanily food for thought but I think something more sincister is going on here.
I don't see why it would run all the time, I haven't seen a air con run all the time in any other cars, toyotas included and the heating cooling systems is extremely similar from what I can see to my passed toyotas.
Monday, February 26, 2007 - 07:13 pm, by: Dave Hart(Davyboy)
Damian; its bound to run all the time if it isn't cooling. Maybe the control valve isn't working, either way you should take it to a well regarded auto a/c specialist.
Tuesday, February 27, 2007 - 06:19 am, by: Matthew Sharpe(Madmatt)
The only cars I've come across that have switching compressors are ones that have an "economy" cycle available on the A/C control - thus when on Economy mode, the compressor cuts out when the car has cooled down. Never seen a Soarer set up like this though.
Mark Ribbans TryHard SA UZZ-031 V8, 1972 Mazda RX2 Coupe, TE Gemmy
Tuesday, February 27, 2007 - 03:10 pm, by: Damian Ware(Frozenpod)
Ok guys there seems to be a miss conception here. My understanding of the aircon system is as below please someone correctly if I am wrong.
If the aircon is turned on the aircon system will always constantly stay on but the compressor clutch will disengage to regulate the pressure in the system.
Why else when sitting in traffic does the RPM go up and down by a few hundred RPM when the compressor disengages and rengages when the aircon system is still turned on. You can also hear the clutch kick in, a small clunk sound on some cars, particularly noticeable on my girl friends pulsar.
I am not talking about climate control as most responses have been referring too, simply manually (the only way to run the cooling system) set the aircon to on vents how you like them and fan speed.
For example maximum cold, air con on and fan speed maximum. In this situation the compressor should cycle on and off even thought he system is still always on. The air will always be cold with some small variation with gas pressure that is not notiable.
Tuesday, February 27, 2007 - 04:09 pm, by: David Vaughan(Davidv)
quote:
simply manually (the only way to run the cooling system) set the aircon to on vents how you like them and fan speed.
Well, I have very rarely run my system like that in nearly twenty years and can hardly imagine why I would, so our understandings of the system may be different
The compressor has no holding tank so far as I am aware, or at least none of any significance beyond what is in the pipework and heat exchangers. Therefore, when the compressor cuts it ceases cooling within a very short period and the compressor will soon cut back in again. Basically, if the car is above desired temperature then the compressor will run until it meets the criterion. If it is below the desired temperature then it will stay off, with some heating applied as necessary, until it is warm enough when the heating will be cut back to maintain balance. Fine control of cooling is managed by controlling fan speed and possibly by addition of some heating to the system, when in Auto mode. It also responds to the solar sensor with anticipatory changes in cooling and heating.
In manual mode, if you ask for Max Cold, that is what you will get until you stop asking for it; no cycling of the compressor. Like Peter says, if in mid-winter you manually crank up the heater and turn on the A/C with air to the screen, you will get all the cooling effort you requested to dry the screen quickly. Under this manual control, the compressor will not switch off until you say so.
I am unable to explain the behaviour of Pulsars.
Dan McColl Goo Roo Victoria Active V8 and a Factory Manual XF.
Tuesday, February 27, 2007 - 04:12 pm, by: Dan McColl(Hoon)
I noticed on mine, if it has too much gas in it, it tends to cycle, as you suggested.
When the gas level is right, it seems to pretty much always stay on.
There are also some actives that don't have a clutch. check yours, I'm not sure which ones do and dont, but some actives run continously ( even when switched off) and use some sort of bypass valve arrangement to control the gas flow to the evaperator.
It does sound like you have a leak, though. With the dye it should be pretty easy to find.
Tuesday, February 27, 2007 - 04:19 pm, by: David Vaughan(Davidv)
I neglected to add at the end (busy signing off with my little joke about Pulsars) that quick failure should mean loss of the compressor or loss of refrigerant gas or no air flow. Two of those are dead obvious, leaving refrigerant. Can they not test the current gas pressure before evacuating and recharging the system? It will be low if you have had a loss, after which you can add dye with the recharge, if you have none in there now.
Tuesday, February 27, 2007 - 09:23 pm, by: Ben Lipman(Ben12a)
Damian,
I have the same problem. I regas the aircon and it works fine for a while. Then if the car sits undriven for a while it loses cooling ability. I take it to the aircon guy and he diagnoses very little or no gas in it. There is never a trace of the dye he put in previously and his super sensitive gas detector can't find a leak. (these sensor things can pick up a couple of parts per million gas).
Over the years I have just decided that $80 regas is small bikkies when a tank of fuel costs the same. Obviously this is no good for the environment and my pride is dented that I have a fault with the car I can't fix. I posted here a some time last year but could not find an answer. I'll have a look and see if I can dig up the thread.
I hope you have better luck than me.
PS: I have the same kick in/cut out thing with the aircon on our cars. I think it may just be the fan (on the radiator/condensor[?])cutting in and out. It definitely is on the Subi as it is all there to see easily.
I just re-read the replies. The next time it goes I'll have to get the guy to run his sensor around up under the dash area to check if the leak is inside the cabin.
Wednesday, February 28, 2007 - 02:52 am, by: Peter Nitschke(Pen)
Damian, get with the program!
The A/C is controlled by an ECU to some extent whether you like it or not.
Using C/C means the ECU will adjust external vents, internal vents, air speed and heating to get to the desired temperature as soon as possible, and will then adjust to maintain it.
You can manually over ride any or all of those functions and the rest are still controlled.
If the car is hot inside after being in the sun, then it won't matter if you have the temp set to 25 degrees or full cold, it will be running at full cold anyway to get the temperature down.
The temperature setting doesn't directly control the temperature of the air coming out, it controls the end result of the cabin temperature that you desire, so as long as the temp is set to anything cooler than what the cabin is, it will go cold with higher fan speeds and closed external vents until it gets close. Then it will reduce fan speed, switch to external air, possibly adjust internal vents, and start to add heat so as not to freeze you.
The whole point of c/c is to save you having to do it manually which is so last century
So if you aren't happy with it selecting recirc instead of fresh incoming air, put the temp down a bit and apart from if the car is very hot inside, it will select fresh - or change to fresh as the car cools inside.
If you aren't happy with the selection of inside vents, just hit the mode button to select what you like.
By switching the A/C on/off all the time, you may be adding wear to the clutch mechanism (probably minor) but you also have the situation of the evaporator inside the car getting cold and collecting moisture, then going warm and giving you a bit of a musty smell and high humidity when you switch it off.
Possibly the frequent temperature changes to the cooling system also adds stress due to expansion/contraction of the various bits, which may increase the chance of stress fractures and leaks.
So it's better for it to be either on, or off, than to be on/off frequently.
Even if you prefer just to run it manually, just adjust the temp knob for desired temperature, as it still works even if you haven't hit the c/c button.
In winter, with all A/C functions switched off, adjusting the temp knob will still affect the temperature of the air coming in through the vents and whether the external vent is selected.
Andrew Ferres DieHard WA '86 Cressida V8, '84 Soarer V8, '90 C-F Celsior V8
Wednesday, February 28, 2007 - 02:06 pm, by: Andrew Ferres(Peewee)
Compressors can also cut in and out when the pressure in the system gets too high.
This happens when the gas in the system gets too hot and expands too much (Southo was saying that in his MX83 Cressida it cuts out at 3200psi, and cuts back in again at 1200psi). http://www.toymods.net/forums/showthread.php?t=13699 The gas gets too hot when there is not enough airflow over the condensor to cool it down. If you have converted to thermo's then this is a very likely scenario. If you are still running the hydro or viscous fan and they are working fine, then its very unlikely (unless the condensor is blocked??)
I'm not sure if the Soarer's system works like this, its just a theory.
As for the compressor cutting in and out to keep the temp constant, I'm not aware of this happening. If the cabin temp gets too cold it will just open the heater tap to let a bit of hot coolant through the heater to warm the air up slightly.
Monday, June 11, 2007 - 10:35 am, by: Tim O'shea(Tim_85)
andrew i think the pressures are more like 320psi and 120psi (it is only thin al tubing). but yes the compressor will switch on and off to to prevent over pressure and on to create pressure, however most of the temp/pressure regulation is done by the tx
Andrew Ferres DieHard WA '86 Cressida V8, '84 Soarer V8, '90 C-F Celsior V8