60 degree delivery temp from A/C no matter what I do

[white99c2]

Phoenix is hot right now, an average of 105+ degrees.
Started off with a '79 SC that had 134A in it when I bought it. It was blowing 60 degrees when cruising at 65 miles an hour in 5th gear. The front condenser fan was not working. I ordered the motor, installed it, purrs like a kitten, still 60 degree delivery temps.
Brought the car to one of Phoenix's local Porsche Guru's. He replaced the 134A and charged it with 48 OZ of R12, guess what; still getting 60 degree delivery temp at the vents. He added 4 - 12OZ cans to 3/4 on the sight glass of the dryer...is that to much?
Back yard engineered ducts that blow just under the dash on the crotch of the driver and passenger from the lower dead center air that was just blowing under the dash, nice touch works well but still 60 degree temps.
Added a return air fan to the hole under the passenger floor board to the smuggler box to aid in better return air to the evaporator, still 60 degree air at the vents.
Removed the smog pump, relocated the coil to make room to add a rear condenser fan, works like a charm, sounds very high tech but still getting 60 degree delivery temps at the vents.
I give up, what the heck is going on with my car, I've got so many fans going on, I may rename it Tornado.
BTW, the blower is on medium when I take the readings.

[Tigerrat]

So you are getting about a 45 dg drop and with R12. I would think you should get better. Easy stuff first, is your thermostat turning off the compressor prematurely? Low, high pressures at high idle? Some components could be old and bad; receiver/dryer, compressor, txv. Did the tech make any adjustment to the expansion valve? Lots of variables. Ken

[white99c2]

He didn't adjust anything. It was delivering 60 degrees at idle and when I left he told me once I get cruising at 60-65 miles an hour the delivery temp should drop to 50-55 degrees.
Didn't happen, it drops to 60 and thats where it stays.

[911nut]

Usually if you have a full charge and still are getting hot air the expansion valve is the likely suspect.
Find yourself a tech who knows what he's doing. There should be a ton of them out there in the desert. Maybe someone here on the board will chime in.

[Porsche80]

Hey I have a 80SC and I get 45 F temps at vents when car is in motion and 58/60 F temps when car is just stationary. However, I can never seem to get car to cool down. I replaced all hoses with new barrier hoses including evaporator/drier also replaced thermostat switch in console. When I replaced all hoses, car was evacuated and recharged with 134a. I did an overnight leakdown and it was good, no leaks. It has both a front/rear condensor and I can hear front fan blowing. My wrench said low side was at about 25 and high side was about 325. What can I do to get car to cool down. In the area I live it gets pretty humid. I have never heard of an adjustable expansion valve. Do you have to evacuate system the system to adjust? What is the process? I looked on Pelican's web site and it says nothing about adjusting the expansion valve. Prior to replacing hoses (these were the orginal leaky hoses)etc. If I charged up system (using 134a) it would last about 2 weeks and seemed to cool pretty good, before leaking out. Clueless

[DRACO A5OG]

My understanding is R134 is very sensitive on accuracy of levels. Too much R134 actually defeats the cool down process.

Verify the numbers and if needed reduce the high side.

R12 is more forgiving.

[Porsche80]

What should the numbers be for a car that has both front and rear condensors? I have a Bentley manual and it says bars? I have not seen any numbers when using 134a. However, from reading multiply threads on this web site and others my numbers are in range and this is validated by the vents temps

[DRACO A5OG]

Here is a Chart http://www.ackits.com/aacf/ptchart.cfm

According to the chart, 25 low side, high side should be 165-270. That would mean you have too much refrigerant

[RSTarga]

I am very dubious about these vent temps that everybody talks about. I have a 91 turbo 964. The air conditioning works great, very comfortable and cools down fast even at 103 degrees where we are at these days. I plugged in an electronic thermometer in the vent and to my surprise I never get down below 55 (at 102 outside) . My 73 is about the same but doesn't really feel as good so what's the difference? The volume of air. So how do we get the older systems to move the same amount of air? By the way I run r12 in both cars.

[JMH82SC]

Originally Posted by RSTarga

I am very dubious about these vent temps that everybody talks about.

This is a pic of my A/C vent temp on full blast #3 setting in my neighborhood on a 98 degree day which does not yield my coldest vent temps in the mid to low 30s in FL 98 plus heat on the low setting.

System is stock with the exception of:
Custom barrier hoses
Used Sanden 508 compressor
New Drier
New Expansion Valve
Insulated Evaporator Box
134A Charge

[white99c2]

RS Targa since I posted this I added 3 small computer fans right on top of the front condenser then mounted the factory front condenser fan in its mount.

It makes a difference I can get down to 55 degrees on the open road in mid day cruising at 60 MPH.

In the morning when temps are in the 90's here in Phoenix I can get down to 50 degrees at the vents.

[Tigerrat]

80, do you know how many ounces or R134a are in it? What's the ambient? 25 lbs is a bit higher than I see on mine here. Was the lid closed or a big fan on the lid cond? 1500 rpms or so?
Adjusting the expansion valve is best left to experts and I wouldn't worry about it unless you think it has already been messed with.

A bit of window tinting helped me as my 88 is marine blue. Ken

[T77911S]

too many hi jackers. it gets confusing trying to help 2 or 3 people at the same time.

to the original poster.
most likely the expansion valve. they are adjustable. but they have to be removed and you have to have an idea of what you are doing. it can get expensive doing a trial and error with one.
the expansion valve also has a bulb that holds a charge of freon. if it losses that charge, it could cause the problem you are having.
when my expansion valve went bad, the low side was higher than it should have been and the hi side was lower. at first i thought it was my compressor because the hi side was so low. it could also be the bulb came lose from the low side line. it should be attached to the low side with a clip and then insulated so it will obtain the same temp as the line.

to the others
more air out the vents will lower the temp out of the vent.

these cars usually have a much higher hi side. especially if there is a rear condenser and the lid is open. i usually place a box fan on the rear window blowing into the rear condenser.
put the freon in by weight is the best method, still monitor the pressures tho

if your temps are getting down in the 30's you may want to check your low side pressure, it may be too low and even going into a vacuum.

when i charged my brothers 930, his low side never got above 12-15 psi. even with different expansion valves, different refrigerants. no blockages, system was flushed. cant remember the hi side, but it was about normal. this last time we used freeze12.