Search found 510 matches

by JohnHere
Wed Sep 22, 2021 8:29 am
Forum: Automotive Air Conditioning Forum
Topic: POA Valve Honking/Pulsing
Replies: 7
Views: 183

Re: POA Valve Honking/Pulsing

When testing a POA with compressed air, you should hear a "pop" when the valve reaches its set-point and then a "hiss" as the air flows through it. The noise and pressure fluctuations that you're seeing appear to be abnormal. Could this behavior be caused by the old internal soft...
by JohnHere
Mon Sep 20, 2021 9:11 am
Forum: Automotive Air Conditioning Forum
Topic: My turn, need the wizards
Replies: 35
Views: 557

Re: My turn, need the wizards

An internally delaminating hose is something else I thought of after I posted, and it is another remote possibility. Only other thing I can think of is the evaporator. MVAC is often not easy to diagnose and repair, as has been said many times before. Let us know the results after you change-out the ...
by JohnHere
Mon Sep 20, 2021 7:41 am
Forum: Automotive Air Conditioning Forum
Topic: My turn, need the wizards
Replies: 35
Views: 557

Re: My turn, need the wizards

Have you verified that there is not an OT installed in the line between the R/D and TXV causng an additional restriction?
by JohnHere
Mon Sep 20, 2021 7:24 am
Forum: Automotive Air Conditioning Forum
Topic: My turn, need the wizards
Replies: 35
Views: 557

Re: My turn, need the wizards

I agree with what DetroitAC said about oil return. In GM POA-valve systems, for instance, as the POA throttles down, oil return is also throttled (reduced)...hence the reason for a separate oil-return line that bypasses the POA. The system in question doesn't have a POA, though, so the oil is carrie...
by JohnHere
Mon Sep 20, 2021 6:47 am
Forum: Automotive Air Conditioning Forum
Topic: POA Valve Honking/Pulsing
Replies: 7
Views: 183

Re: POA Valve Honking/Pulsing

Matt, your POA valve could be defective as mentioned. But before presuming that it is, I would test it again using reduced air pressure of around 60 to 80 PSI. The pressure you used, approximately 100 PSI, seems too high to me when you consider the pressures at which the low side typically operates....
by JohnHere
Sat Sep 18, 2021 10:06 am
Forum: Automotive Air Conditioning Forum
Topic: My turn, need the wizards
Replies: 35
Views: 557

Re: My turn, need the wizards

I did not weigh it in, but I am gonna guess about 24 oz. I started with a 12oz can liquid into the high side, as always, then topped off on the low with my jug. The charge amount of ~24 ounces does sound a little light to me. For a custom system like that, just off the top of my head, I'd expect it...
by JohnHere
Sat Sep 18, 2021 8:36 am
Forum: Automotive Air Conditioning Forum
Topic: My turn, need the wizards
Replies: 35
Views: 557

Re: My turn, need the wizards

Thanks, John, there really isn't an OEM TXV per se, all the components are aftermarket, the car never had AC. I have tried 3 different TXVs (sourced differently with stated different manufacturers). Same results. All are 1.5 ton rated Yes, I remembered your saying that the car never had A/C. I was ...
by JohnHere
Sat Sep 18, 2021 7:43 am
Forum: Automotive Air Conditioning Forum
Topic: My turn, need the wizards
Replies: 35
Views: 557

Re: My turn, need the wizards

I'm thinking about the TXV again. Perhaps the one you're using from Ranchu just isn't calibrated for this application and not metering properly. It's possible. I've had problems with non-OEM TXV's in the past. Might be worth trying an OEM unit (if you can find one) or a correct OEM replacement, whic...
by JohnHere
Sat Sep 18, 2021 6:07 am
Forum: Automotive Air Conditioning Forum
Topic: POA Valve Honking/Pulsing
Replies: 7
Views: 183

Re: POA Valve Honking/Pulsing

Welcome, Matt. For R-134a, I believe the POA needs to be calibrated to 26 PSI to work properly. Search this Forum for the specific procedure, which has already been discussed and pictured in detail.
by JohnHere
Fri Sep 17, 2021 8:58 pm
Forum: Automotive Air Conditioning Forum
Topic: My turn, need the wizards
Replies: 35
Views: 557

Re: My turn, need the wizards

Several things come to mind. Here are a few: The first concerns the TXV sensing bulb. Are you sure that it's securely attached to the outlet tube of the evaporator and that it's completely covered by Prestite tape? I agree with you...I don't think the TXV is otherwise malfunctioning. With a low pres...