A/c Problems

[rich 91 ls400]

Hey just joined the club today and I have been searching the archives i need help ,this site is great. Hello, I just recently purchased a 91 ls 400 it is in great condition and I love it. Only 2 problems. My a/c is not working very well. granted the car is old, I am using the mechanic that the gentleman I purchased the vehicle from recommended. First the a/c had a leak He tried to fix it with 134a freon with the sealant , he put in 2 cans of the sealant freon. worked great for two days then no a/c. Another 2 cans of freon with sealant same result. finally 2 more cans. Then he replaced the main line and leak is fixed. The problem is that it is not blowing as cold now as it was the first few times he added the sealant freon, and now the a/c compressor seems to be kicking on and off alot. When the car is iddeling (sorry about spelling) the a/c compressor kicks on for about 20 seconds then it's off for just a few seconds, then it's right back on. It gets really irratating when i'm sitting at a stop light. Kicking on and off. A/c is not that cold and I am worried about damage to the compressor and or other components. Any advise??

[cro_med]

It seems to me your refrigerant level is low, have him to add another can of freon.

[wwest]

Hey just joined the club today and I have been searching the archives i need help ,this site is great. Hello, I just recently purchased a 91 ls 400 it is in great condition and I love it. Only 2 problems. My a/c is not working very well. granted the car is old, I am using the mechanic that the gentleman I purchased the vehicle from recommended. First the a/c had a leak He tried to fix it with 134a freon with the sealant , he put in 2 cans of the sealant freon. worked great for two days then no a/c. Another 2 cans of freon with sealant same result. finally 2 more cans. Then he replaced the main line and leak is fixed. The problem is that it is not blowing as cold now as it was the first few times he added the sealant freon, and now the a/c compressor seems to be kicking on and off alot. When the car is iddeling (sorry about spelling) the a/c compressor kicks on for about 20 seconds then it's off for just a few seconds, then it's right back on. It gets really irratating when i'm sitting at a stop light. Kicking on and off. A/c is not that cold and I am worried about damage to the compressor and or other components. Any advise??

Compressor is automatically cycled off if:

1. High side pressure is high enough indicating sufficient liquid "store".

2. Low side pressure is too low indicating lack of sufficient refrigerant charge.

3. Evaporator surface temperature has declined to or below ~34F

4. Engine coolant temperature is approaching criticality.

5. WOT

6. OAT is below freezing.

What you describe may very well be TOTALLY normal operation.

So as to not discomfort the passengers the Lexus NEVER blows very COLD airflow except at 65F setting, maximum cooling, and manually set low blower speed.

Once the cabin atmosphere is cooled to near, within a few degrees, of your setpoint the remix/reheat cycle is set to provide only moderately cool "maintenance" low volume outlet airflow.

You can quite radically inprove the A/C efficiency, and substantially improve FE, during the summer months by disabling the reheat capability. Remove the push/pull remix/reheat door servomotor link cable from the water flow control valve at the top center of the firewall in the engine compartment and twist-tie it, the valve, into the fully closed position.

No HOT water flow, no WASTEFUL reheat capability....

[rich 91 ls400]

Thank you guys for your help. I was just worried that the freon with the sealant will do damage to my a/c system. It just seemed strange that it was blowing colder while the system had a leak. I may have had it on 65 degrees though. I love this club and will continually visit it to keep abreast of possible easy fixes of problems. I was real interested to see people hooking up their ipods to the stereo.

thanks again!