911PERVY

Does the air con compressor cut off when engine is on full throttle/boost?

Mark993TT

I don't think it should. What's the issue?

911PERVY

On full load (full throttle and full boost) the compressor turn off and no air comes out of vents. When not on full load air is nice and cold.

Quadcammer

yes, this is very common

911PERVY

Common? OK, should it happen? Is it a common problem? Why is it happenening?

911PERVY

Looks like it could be this;

https://rennlist.com/forums/showthre...ferrerid=10902

I just cant believe that the a/c should stop under load, 408bhp should be ok to run a little compressor!

Quadcammer

Just about every car out there shuts off the a/c compressor at full throttle to reduce the load. There may be a switch you can bypass to leave it on.

Mark993TT

A few weeks ago I had the same issue. Turned out to be a faulty vacuum valve. A relatively easy/not that expensive fix. Now it works fine, keeps blowing cold air also on wot (like it should).

Felix

The load on the AC clutch to switch on and off at full throttle (which often means high revs) would not be good for its longevity.

As others have suggested look for an issue with the vacuum circuit.

djantlive

how long are you on full throttle anyways? compressor should cut out but that doesn't mean the fan for the cabin should stop. you should get cold air for 30-45 seconds after the compressor is off so disruption shoudl be minimal.

Giuscripa

My car was exactely like your from 2 years and today I solved the problem: the vacuum lines in the engine were connected wrong. Two of them was changed. The vacuum lines begin in the back of the throtle body. In one of them there is a round valve (one way valve). The vacuum line that goes to the front of the car with the wires from the engine, located on the left side of the engine, should come from the line that has the one way valve. Otherwise, when you step, the vacuum desapears and the recrculate flap closes, giving you no air.

Giuscripa

My car was exactly like yours from 2 years and today I solved the problem: the vacuum lines in the engine were connected wrong. Two of them was changed. The vacuum lines begin in the back of the throtle body. In one of them there is a round valve (one way valve) right behind the throtle body. The vacuum line that goes to the front of the car with the wires from the engine, located on the left side of the engine, should come from the line that has the one way valve. Otherwise, when you step, the vacuum desapears and the recirculate air flap closes, giving you no air. My car also had a fuel pressure problem. Around 4.000 rpms it was heading (not enought fuel). That was because the vaccum line that connects in the fuel pressure regulator instead of beeing connected directely in the back of the throtle body, was connected in the line that has the one way valve. I changed them (cabin x fuel pressure regulator) and both problems were solved. I printed the pet diagram from porsche website and followed all the vaccum lines in the engine to discover that. You can do the same. Intercooler out and hot air box (left side) out. Good luck!