Finally got around to checking the charge level of the AC system in the car today.

It's currently about 85 degrees F outside right now, and the low side is showing 35psi with the gauge I got with the refill kit at Autozone, right in the middle of where it's supposed to be. I sat in the car idling for 15 or 20 minutes with it set to max AC, high blower speed, and it never did get cold in the car. It really didn't feel like it got much cooler than ambient, maybe down to 70 degrees, if that.

The compressor turns on and stays on no problem, and I'm getting decent airflow from the blower. Does freon eventually lose it's ability to cool (as in I should evacuate/recharge the system)?

 

If its for your 93Z, it might be time to replace the dryer(accumulator) and expansion valve and have the system flushed..

I had this done to my 93Z, but instead of regular R134A, I used this;



I showed a 3~5 degree drop in temp...

 

I wonder if I need to do the same thing, n2ceptor.

My A/C hadn't worked for a couple of years. Since the car wasn't a DD, I didn't worry about fixing it. At first it just started blowing lukewarm air, but the compressor was on. Then when I tried using it again later, I noted that the compressor would not even kick on (which I figured was due to the system pressure being too low and not tripping the pressure switch).

The other day I decided to try recharging it, since I'm driving the car more now. I hooked up the filler tube / gauge / valve and the can of R134a. The system pressure read below 25 psi (I think it was around 10-15 or so), in the "add refrigerant" section of the gauge. I added the can of refrigerant, and by the time the whole can was empty (stopping and checking the pressure periodically as I filled it), the gauge got into the "OK" zone. The compressor had started working again, and in the car, I got cool (but not cold) air.

I drove it to work the next day, but it already wasn't blowing much cool air. I figured maybe the leak was just that fast now (though that didn't make sense, since there was still pressure in the system when I started all of this, and that was after a couple of years of not working well). Last night I checked the pressure again with the gauge, with the engine running and the A/C turned on (and compressor running). The low side pressure was way high, into the red - something like 75-100 psi. How did that happen?

Anyway, today I had a Tech II hooked up to the car to see why my check engine light was on (P0400 EGR code). There was also a P1543 code (A/C refrigerant low) present, which made sense, because it had been low for a long time. With the engine idling and warmed up, I took a look at the live data display. The high side pressure was reading 604-650 kPa (1.10 V) with the compressor on, and about 500 kPa (0.94V) with the compressor off. The A/C Evap Temp read 32 C. I don't have my service manual in front of me - it's at home - so I'm not sure how good or bad those numbers are. Any ideas, anyone?

If I do need to replace the dryer (maybe the moisture absorbing material has lost its effectiveness), is it a difficult fix? Is the part expensive?

Thanks!

 

Anyone? It's hot outside...

 

I noticed on mine it took about about 5 minutes of running the AC before the gauge stabilized right around 25psi...it started out closer to 10psi. I just checked the AC vent temp last night around midnight, it was about 65F (no wonder it never got "cold" in the car, lol). I'm planning on replacing the drier and recharging this weekend.