Air Conditioning problem in 1993 Civic DX

[RonJ]

The service manual says to run the engine at 1500 rpm when measuring the low and high side pressures.

Based on the chart, your high side pressure is way low and your low side pressure is way high. With the caveat that your engine was running at 1K rpm, the service manual says that your reading may indicate a bad compressor or expansion valve (or other possibilities).

After you turn the engine off, do the high and low side pressures equalize rapidly or slowly?

 

[tjwebb]

I did not observe the speed at which the pressures equalized when I turned the engine off. Curious that the chart I had said my pressures were ok. Where can I see this table that you are looking at with the pressures? I don't see them in the table you posted.

I did not replace the expansion valve when I replaced the compress/condenser/dryer. Do you think there is sufficient evidence to warrant its replacement as well?

 

[RonJ]

The vertical blue line is the outside temperature.

The thick horizontal red line is about what the high side pressure should have been.

The thin horizontal red line is what the high side pressure was.

The thick horizontal green line is about what the low side pressure should have been.

The thin horizontal green line is what the low side pressure was.

Conclusion: High side was too low and low side was too high.

 

[RonJ]

I did not observe the speed at which the pressures equalized when I turned the engine off.

You should check it.

Curious that the chart I had said my pressures were ok.

The chart you have is generic. The chart I posted is for your Civic (taken from the service manual).

Where can I see this table that you are looking at with the pressures? I don't see them in the table you posted.

See post above.

I did not replace the expansion valve when I replaced the compress/condenser/dryer. Do you think there is sufficient evidence to warrant its replacement as well?

Not yet. Gather more information. See Table in post #21.