I currently have Freeze 12 in there - the guy whom I bought it from filled it ....

In any case, the cooling REALLY leaves something to be desired. The compressor comes on, and seemingly is working all the time, and the condensor fan also works... OK. Here are some numbers:

Ambient temperature was 80 degrees

Without the engine running, and fully equalized - Pressures are 110 psi/ 110 psi (Low / Hi)

At idle, the pressures are 14 psi / 165 psi

At 2000 RPM Pressures are 9 psi / 210 psi

How shall I proceed? Are these numbers indicative of a blocked expansion valve? OR, a low charge ?

Thank you in advance,

It would appear your expansion valve is working or you would not have such low numbers on the low side.

You might check the monovalve. If that is leaking you will get hot coolant in the heater core and off-set the benefit of the evaporator.

Does the A/C work well when the engine temp is low, such as when you first start it? and poorly when the engine is warm?

Does the A/C produce different vent temps depending on you speed (as it relates to engine RPM working the water pump harder, thereby pushing more coolant into the leak)?

If your monovalve has a slight leak you could only have the problem at higher engine rpm.

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Thanks. It does seem to be blowing colder before the engine warms up, however... here is some more info...

In general, A/C works better in highway speeds / freeway, and it is nearly useless ( barely colder than ambient) in traffic, or when stopping still... Revving up the engine just a tad does seem to make the air a bit cooler.

About the pressures.... Are they normal? Is the low side supposed to be that low ??? The high side seems OK... ( approx 2Xambient + 15%)...

Freeze 12 has alot to be desired as a R12 coolant alternative. I never got real good cooling from it. Your low side sounds a bit low. R12 ran about 30-35 psi low side and up to 275 psi high side.
Check the pressures at about 1200rpm.
PM me and I will tell you what I use. I DON'T want to get into a refrigerant debate...... AGAIN!

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