axl911

All,

After hooking up the AC gauges on the high and low, am I supposed to rev to 2K RPM to read the pressure? And do I have to hold it there? Should the pressures drop after releasing the gas and allow the car to idle again (with AC compressor still on and running)?

The manual states that "the pressures specified in the diagrams must be reached after approx. 10 mins operations time at a speed of 2K rpm with the compressor switch on."

thanks,
anthony

race911

I've never really run-up (for an extended time) any cars I've checked/serviced. Not sure if they're looking for you to establish an absolute pressure with a heat soaked condenser or what. I've always looked for appropriate pressure v. ambient at idle. And vent temperature.

Admittedly, most of my experience is with R-12 systems when I had my shop in Phoenix in the '80's. Everything I do now, which is minimal, is just kind of by feel.

axl911

Ambient is 75 degrees.

Picture below is what I am seeing when car AT IDLE after it has sit for 10 minutes after I got home. AC was running during the drive home. Lo side 25, high side 225.

axl911

Next is revved the engine to 2500rpm for a minute and let it settle back to idle. Now i am seeing 32 on low and 265 on the high side and pretty much stayed there.

Sooo..... are these pressure too high? Am I supposed to keep the car revved up to 2000rpm when reading the pressures?

The car's AC has been lacking in performance.

epj993

Anthony, you may have seen this already but our own Brian Smith did an excellent writeup for A/C diagnostics. It includes high & low pressures as well as very detailed troubleshooting info.

axl911

What I was looking for. Thanks!!!