It sounds to meyour talking about the compressor intentionally cutting out when @ 50% or greater throttle.
Granted, the A/C system in these cars is not anything to rave about, but if that's what it is, perhaps just keeping a lighter foot on the thin-pedal through the hot months will solve this problem for you.

 

are you serious ?
70% of the days here are very hot (>28c), you are expecting me to drive like an old lady 70% of the time just because of the A/C bad design ?
This is hardly an acceptable solution..you might as well tell me to stay at home so I don't feel the heat, or drive just at night time..

 

'Sorry, but if that's the effect that you're feeling, and you do say you drive aggressively, then that may be the cause. I'm not there to feel what it is you are compaining about.But I know here in Texas, my A/C has a hard time keeping up too. It's probably my single biggest complaint about it.
On the 100+* days, the car is usually cooling down nicely just as I'm pulling into my driveway from a 25-30 min trip home. It's frustrating, but it is better than nothing @ all.
On the other hand, I drove sports/sporty cars for years, and @ that time we wouldn't THINK about giving up power and economy for A/C... especially power.
All modern cars are designed like that. I'm not sure if it's a madate or not, though it probably is. It allows the car better power when needing to accelerate hard, and better fuel economy too.

 

Virgin1 you should get in touch with billm about the A/C mod. He lives in Texas too, so you're really close.

 

Thefact that Mazda 3 has a Wide Open Throttle A/C Cut-Off Relay Circuit is an intelligent feature IMO. Fact is,many if not mostcars these days have this circuit. Is Mazda's different than the others? I'm not sure, it could be.

Your generating a lot of heat with the throttle wide open, in order tohelp your cooling system to deal with this, it shuts off your AC if you have the throttle wide open for longer than a set time. Would you rather expose your engine to a possible overheat damage situation?

Another point is, if you don't want to void your warranty, be careful about how highyou rev your engine. There is a sensor whichmonitors engine RPM, and ifyou rev itpast redline, the computerrecords the fact. If you ever try to make a warranty claim, the Mazda tech will check the data to see if youpushed the engine RPMsover the max. If you did,your claim can be denied. FYI.

 

I read that entire thread and I applaud the effort on both your parts. Iirc, you had something to do w/it too, didn't you, or were you just the first to try the "production" model?

 

OK, I really don't accept the answer that this is normal and logic functioning of the system. Few facts to support this :

- The same model with 1.6 engine doesn't show this behavior.
- I drove more than few other cars, sport cars, very aggressively - none had a problem with that.
- Mazda admit that the only purpose for this feature is to give the driver maximum power when he requires. BUT :
This is not a simple throttle dependent relay. As far as I can tell (I'm an electrical engineer, just FYI..),
this is a design problem, which 99% of the users don't see since they don't have the same "profile" as I do.
For example - if the A/C cut-off was only throttle dependent, you would expect it to behave the same on all weather. But, I did some experiments - I have a long up-hill road near-by, ifI go up this road at a hot noon hour, even if I'm not at 100% throttle all the time - most of the way up, the A/C is off, this was also confirmed by Mazda engineer who took a drive with me, while the computer is connected and monitoring the A/C status. He did see the compressor cuts off, but he said it's normal behavior.
If I drive the same road at night time, in a more cool temperature - even if I push the car 100%, the A/C almost never cuts off, and if it does, it's for few seconds, as it should.
Sometimes I need to drive 3-4 hours accross the country, most of the road is desert climate, in the summer it can get to 40-45c, this is a real nightmare - the road is a pleasure to drive, nice curves and asphalt, but if I'm tempted to push the car just a little bit - I get punished by the A/C - it can cut off for 100% of the time if I don't relief the throttle. This is by no means a desired behavior, or something I encountered in other cars.
I tried this with another Mazda 3 2.0L - same behavior exactly.
I suspect that one of the sensor, or actualy the threshold - for example there's a sensor for the fluid temperature, if it's too high the compressor cuts off. Now if the threshold is set too low this can explain the behavior and the dependency on ambient temperature.
Again- the cut off is not 100% correlated to wide open throttle, as the ambient temp rises, the throttle position that cuts off the A/C is lowering. i.e at 40c ~60% throttle already cuts the A/C.

 

Well, you may be right, and I am not an electrical engineer, just a "couch" engineer.
All I know is that when I push my car hard w/the A/C on, not necessarily to 100% throttle either, the compressor cuts out briefly. I'm not happy about it, because the system takes forever to recover from that. But, I like the car, so what am Igoing to do?
I own an '04 hatch w/the 2.3L and a 5-speed. And too, as I've stated before, the A/C leaves a lot to be desired in the first place, imo. But, these are not luxury automobiles (THANK GOD!!!) I can't stand that soft squishy ride and the feeling like I'm driving a double water bed instead of a car.
I'm sorry toeven be suggestingthis, but perhaps you have simply chosen the wrong car for your situation?

Apart from that, you have piqued my curiousity. Where are you? What country?

 

A couple things to get specifically checked out:

A)Make sure your auxiliary fan is working properly.
B) Air conditioning systems have a Limiter switch, which shuts the compressor off when the pressure within the system gets too high. This could be what is causing your compressor to cut out. Either the Limiter switch could be faulty, or your AC system could be overfilled with refrigerant, causing the excess pressure condition to frequently occur.

Like anyone whowants to drive extremely, and getracing like performance from the their auto, you may need to make a modification or two. A few ideas.

1) Replace your current spark plugs with cooler plugs
2) Remove the top plastic cover from the engine to allow air to move around the engine compartment more easily to assist with cooling
3) Replace your coolant thermostat with one with a lower temperature setting, just to make sure the coolant is always flowing.
4) Replace your current air filter with a performance air filter, or add a performance Cold Air Intake
... if your car can suck colder air more easily,you might run cooler.
5) Add an oil cooler
6) A weird solution, some people in extreme climates use rubber washers to prop the front of their hoodopen by 1/4 or 1/2 inch on an older car, to allow more air flow into the engine compartment. This sounds unsafe to me, but some have done it.

 

virgin1 - My expectations from the car A/C system are the same as with any car I drove. I had Focus 2.0L for 3 years, with same kind of driving, and no problem. I get to drive many cars, some "regular", some more "sporty" - I never encountered such a problem. BTW - I mentioned already I live in Israel.

Urbanman - I think your suggestion regarding the limiter switch makes a lot of sense. since the cut-off point depends on ambient temp, and engine revs (throttle) - both influence the refrigerant pressure. It's either the unit itself or the threshold set in the computer (set too low).
How can I verify this ?

Regarding the other stuff - I don't have any engine temp problems, even at the hottest days and hardest roads the engine is able to cool itself with no problem. Plus I can't make any extensive mods since it's a company car...