Cool! I think you linked this to me last year when I first got the car and wanted to fix the A/C but didn’t get around to it. The link takes me to a form, I guess you would just fill it out and someone gets in touch with you? Do you know/remember about how much it cost?
I went back and re-read your first post,
is discharge hose still bouncing when compressor engages? those hoses can collapses just like a brake hose and cause a restriction and high pressure.
from temps you reported from temp gun, you have lower pressure in condenser (70 psi at bottom and maybe 125 psi at top) and is working properly.
did you try running cool water on condenser? and if so did pressure change? if no pressure change, issue is probably before condenser (discharge hose or compressor)
but also I have to ask a few basics questions,
- is a proper fan shroud installed?
- expansion valve is it properly insulated/wrapped?
- is expansion valve sensing bulb attached correctly and in correct location?
I have to ask, how did you tested open/closing function of the expansion valve?
I almost forgot it did this. No, it hasn’t done it since I made that post. I had the hose off when I flushed the system and it was clear, but obviously there was no pressure in it then so maybe something changes when it’s hooked up and the compressor is on? If I put my hand on the hose I feel a pulsating in it, not sure what that indicates.
That’s good to hear! I’ll just send the one back that I ordered I guess
I was going to do this last night, but I’ve been getting frustrated with this A/C project and didn’t feel like looking at it so I took the night off, will do it tonight and report back with results. How can I test or tell if it’s a problem with the compressor?
- Yes, I installed a repro fan shroud right after I got the car
- No, the expansion valve is not currently insulated/wrapped. It was unwrapped when I got the car, I had the valve to replace o-rings and I planned on getting the proper insulation once I got the system fixed.
3.I’m not sure if the bulb is attached correctly or not, but I think it is. I put it back in the position it was in when i got the car- clamped onto the evaporator outlet tube. I can take a picture and post it when I work on it next, which hopefully will be tonight.
I read online a couple places that you spray refrigerant on the bulb and try to blow air through it which I did and when the bulb got frosty cold air wouldn’t come out of the other side of the evaporator core, but when it started to thaw out air would start coming out again.
Came home from work and messed around with the A/C for a while. I fired the car up, hooked up the gauges, turned on the A/C and after about a minute or so the high side got up to about 300 so I set the garden hose on mist and squirted it right at the inlet of the condenser, the high pressure instantly dropped, down to maybe 200 or so.
What is weird is that after I put the hose to it no matter what I did the high side never got higher than about 300 without water. I even had my girlfriend hold the gas to what I’m going to guess was around 2000 rpm and the pressure never got higher than 300 without water on the condenser. I did notice when she was holding the throttle that the high side gauge would rise and fall a little- see youtube video link below, not sure what’s up with that. I also heard the discharge hose smack around a couple times as soon as the car started with the compressor on which it hasn’t done since I did the first charge on the system and discovered the high pressure problem.
Anyone have any ideas what was up with the results I had tonight and what should be my next step?
Someone earlier asked about the tx valve and sensing bulb, this is as it was when I got the car and I put it back the same way
you need to wrap that entire thing with insulating tape
Thanks for the link! I plan on wrapping it as soon as I get the system running properly.
The lack of wrapping will affect the temperature sensed by the bulb and the operation of the expansion valve. I just can’t say how much it will affect it and whether or not you’ll be able to get it running properly without it.
I had the same thought, but honestly thought the temp of the bulb would be higher from engine heat, not shut the flow of refrigerant off and cause the evaporator to freeze up. I haven’t gotten that far, but it’s a good thought to keep in mind for when I put a full charge in it. I will probably go ahead and order some of that wrap now.
I read thru this post, If he did not weigh in the freon, could he be just over charging the system? He originally just charged it via the low side, maybe there is just to much?
It is more sounding like the expansion valve. opening/closing at wrong temp or closing too much. (iirc they should never completely close off flow)
A test you could do if system still charged. Since you already tested function of expansion valve, test function while it is running and watch pressures.
with valve open, high side should lower and low side should increase.
Yesterday I installed a new expansion valve, checked the system pretty thoroughly with shop air to make sure there weren’t any restrictions anywhere, replaced any o-rings that looked questionable, pulled a vacuum, it held for a few hours, charged with 2 1/3 12oz cans of R12. The high side restriction appears to be gone, after the car had been up to operating temp for a while my pressure were 32 and 225. evaporator in/out lines were sweating as well as the low side service valve and hose on the compressor and there was a steady drip of water coming out of the evaporator drain.
Unfortunately the air in the cabin never got much cooler than ambient. I believe I have a problem in heater box or somewhere else, but I will start a separate thread about that.