Car ac not cooling when weather is hot.

[Tim]

No need if you're using the same setup. You need to address the condenser issue.

[tbirdtbird]

I think the problem has been discovered quite nicely.
Thanks to your observations.
The pipes/hoses to the condenser are installed backwards, it will never work right, if at all

[Cusser]

I did a test the the problems I found were that the inlet and outlet temperature in the condenser were nearly the same, the difference was about like 5°C, but I'm gonna do another test with the all the conditions and gonna take note of all the temperatures to post them here.

5°C difference seems quite low to me. The condenser needs to cool hot refrigerant gas phase to liquid refrigerant.

1. Were the condenser fittings installed properly?

2. Is the electric fan (or fans) directing the air flow through the condenser rearwards towards the engine?

Condenser: Discharge line always on top!!!!!!!!!

I think the problem has been discovered quite nicely.
Thanks to your observations.
The pipes/hoses to the condenser are installed backwards, it will never work right, if at all

Now you know what must be done. New lines for the condenser can be made too, if necessary.

[tbirdtbird]

Thank you for updating, hardly ever does anyone do that! It helps everyone else

[Tim]

I already mentioned that the large line on the condenser is always on top.

[Cusser]

Should I check if the evaporator is connected correctly?

Evaporators typically have a large connection and a smaller one.

Besides having an "in" and an "out" direction, a drier must be mounted essentially vertical.

Yes, the condenser needs to be plumbed the right way, get that taken care of. There should have been instructions in the kit, but if the installers were qualified in AC, THEY SHOULD HAVE KNOWN THAT.

[tbirdtbird]

There should be specs available for both gas and oil for a 1990 civic

https://piketransit.com/honda-civic-ref ... t_Capacity

[JohnHere]

According to the specs that I have, 31 ounces net weight is the correct amount of refrigerant (R-12) for a stock 1990 Civic and tracks with the information tbirdtbird provided. It also takes 4.5 fluid ounces of mineral oil.

I didn't re-read the entire thread, but I presume that you want to charge it with R-134a and PAG oil.

If you already have the correct amount of PAG oil in the system, charge it to about 75-percent of the R-12 spec (23 ounces) and see how it runs at 1,800 RPM, monitoring the center vent temperature, the pressures, and taking note of the ambient temperature.

If the system's cooling performance is still unsatisfactory at 23 ounces, add one ounce of refrigerant at a time until the vent temps drop into the comfort zone--approximately 40-45 degrees F. or 4.4-7.2 degrees C.--and the pressures look good. Be sure to give the system about five minutes to stabilize after adding each ounce of refrigerant.

Since this is a custom system, we can't know for certain how much refrigerant it holds because there aren't any specs for it. So you'll have to work the charge up slowly by trial-and-error until you reach or barely exceed the sweet spot.

[ice-n-tropics]

FYI: Civic engine rotates CCW. SDS508 Sanden spec is CW rotation because of gear engagement timing verses piston TDC. Timing has a large effect on compressor noise and may decrease compressor life 10% to 25% but pumping capacity is OK.
Chinese knockoff rotation unknown.
Sanden Singapore makes one model SD508 that is rated CCW only.
hotrodac

[tbirdtbird]

Hmmmm.....