I have a 1996 Accord EX, with 344K. I have owned the car for 4 years and the air conditioner has never work well. Today I got the proper adapters to hook up pressure gauges to both the high and low sides. The conditions that we started with were:

Ambient temp: 93 deg F. (In front of the condenser)
Engine speed: 1500 RPM
Low pressure: 22 PSI
High Pressure: 210 PSI
Temp at the center vent: 64 deg F. (Blower on High)

It looked as if the low pressure side was down, so I added 11oz. of R134a. This changed the system pressure's at the following:

Ambient temp: 93 deg F. (In front of the condenser)
Engine speed: 1500 RPM
Low pressure: 32 PSI
High Pressure: 260 PSI
Temp at the center vent: 62 deg F. (Blower on High)

I am wondering why the evaporator did not get any cooler I suspect a faulty expansion valve, but I am not sure. Any help would be greatly appreciated.

Thanks!

 

on the low pressure side you are supposed to have 45 psi. is your compressor clutch engaging when you turn the air on?

 

Yes, the clutch is engaging properly. I have not seen the clutch disengage when the A/C is on (No cycling).

 

Have you check the blend door adjustment.....

 

I have not, but I will check the blend door today. Ill let you know what I find.

 

make sure to take the low pressure up to 45 psi. that should do the trick

 

Rice4life is wrong.

Your system pressures looked good on first measurement.

Low pressure side of R134a system should be in mid 20's for best cooling (just what you had). The fact that you're not getting cooling suggests that something is wrong w/ heater core valve (always on, check valve is fully closed when heater control is on full cold).

You are now overcharged after adding 11 oz. You will need to lower pressures. I usually shoot for 2.5*ambient air temp (degF) on high side and 25-30 on low side at same engine/AC conditions you use. Middle vent air temp should be able to pull down to 40-45F if you're in the shade and car is fully cooled. This is 35-40F pulldown from air temps on floor of pax side. System should be cycling on/off in this condition.

good luck

 

The humidity can change the performance of the a/c system. Cooling moist air takes more energy, compared to dry air.