Honda CRV 1999 A/C issue. Pressures not ok. Not cold at idle speed.

[Gabriel]

Hi, I bought a used Honda CRV 1999. It was not blowing cold air at idle speed. So I removed all the Freon, vacuum and charge the system with 730g of R134A (manual says 700g-750g of charge).
The pressure readings are the following (around 80F-85F outside temperature):
At idle speed (700 rpm): Low=80psi to 90psi , High=160psi , air coming out at 77F
1500rpm: Low=45psi , High=220psi, air coming out at 64F and going down
2000rpm: Low=30psi, High=275psi, air coming out at 57F
>2500rpm: Low=18psi, High=350psi, air coming out at 50F
Pressure still goes up and cuts off the overpressure switch.

Seemed like overcharged (even I charged the amount stated in the manual) so I took of refrigerant until I get 25psi at 1500rpm-2000rpm, but the system had even less performance, air hotter than before when full charged, but is not reaching the point of over pressure (In fact I think in one of the tests the compressor cut off because of low pressure)

It looks like with the full charge (700g to 750g) both low and high pressures are high , or the high pressure is just about normal but the low pressure is high.
When I shut down the A/C the pressures almost do not equalize, they stay at the same pressure before turning of the A/C, and low pressure moves up very very slowly, it takes a long time to equalize.
Condenser is clean, both fans (radiator and condenser) running ok. I can see thru the sight glass in the drier some bubles (one per second let’s say)

I’m still not sure what the problem is. Is a compressor problem? TXV? Drier?

I’m not familiar with car A/C systems, though I do work with residential A/C and refrigerators for living

Any suggestions will be appreciated

Thanks!
Gabriel from Argentina

Topic

[Gabriel]

Another thing to mention. I took off the A/C filter in the passengers side so I could see and touch the TXV. The TXV was not freezing, was only cool to normal, as it is the case for the evaporator and aluminum hoses.

[Rahul Jones]

My friend had a similar problem with his Toyota Yaris. Initially, the symptoms were low cooling so when I checked it was low on refrigerant. I topped up a little and the low side pressure started climbing up on idle that the compressor would shut down. Then we recovered some refrigerant and the cooling level went low. Then we changed the AC compressor as we had a used one lying around. Then it was fixed.

[Gabriel]

In my case, the compressor does not shut down at idle speed. It only shuts down when I rise the rpm around 2500 or above (and the car parked not moving) rising the high side above 350psi. At idle I have from 70psi to 90psi in the low side and 160psi in the high side.
80F outside.
When moving and slightly accelerated rpm (over 1000rpm) at least from the driver’s point of view, the air is somewhat cold almost fine… but when stopped due to traffic, red light or whatever there is no cold air. And I’m not sure what will happen when hit the route at 120 km/hour with about 2500-2800rpm. I will need to test that for sure Maybe moving there is more air flowing thru the condenser and the pressure will drop.

Thanks!

[Author]

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