[haaken675]

Hey everyone. I have an ENTIRELY brand new a/c system in my car from condenser, evaporator, compressor, lines, etc.....

For some unknown reason, the a/c will stop working after a good pull and wont seem to kick back on until the car is stationary at idle. I can't seem to figure out why. It has to be something electric, but i don't even know where to start at this point.....I try turning the compressor on and off while driving, sometimes it works, most times it doesn't.

Anyone have any idea where to start here? It's Florida and hot.....

[alpinec1984]

the air blows constant the whole time, and just the temperature of that air changes?

[haaken675]

Originally Posted by alpinec1984

the air blows constant the whole time, and just the temperature of that air changes?

Blower runs the same with no change. It would seem that the compressor is getting a signal to turn off but not one to turn back on. I'm pretty sure most cars turn the compressor off under WOT, but i don't understand why it wouldn't kick itself back on.

[lookalikehuuh]

This is interesting, sounds like there might be a communication issue with the compressor most likely. I would start by trying to find a way to test the communication back to the compressor while it's in the failed state, I assume this means setting everything up beforehand, making a pull and logging reults before/during/after.

Is the new compressor an OE/OEM piece or aftermarket piece/brand?

[haaken675]

Originally Posted by lookalikehuuh

This is interesting, sounds like there might be a communication issue with the compressor most likely. I would start by trying to find a way to test the communication back to the compressor while it's in the failed state, I assume this means setting everything up beforehand, making a pull and logging reults before/during/after.

Is the new compressor an OE/OEM piece or aftermarket piece/brand?

The compressor is a brand new nissens valeo style unit. There don't seem to be any codes at all that I can find. Checked immediately when i pulled into my driveway. Super weird.

[gbalthrop]

Originally Posted by haaken675

... I have an ENTIRELY brand new a/c system in my car from condenser, evaporator, compressor, lines, etc... For some unknown reason, the a/c will stop working after a good pull and wont seem to kick back on until the car is stationary at idle...

First question that occurs to me: WHO installed "ENTIRELY brand new a/c System" and WHY? If NOT YOU, then ask installer. If YOU, get INPA or Manifold Gauges so you can properly diagnose it.

Most likely suspects are (1) Refrigerant Over-charge, or (2) Bad Refrigerant Pressure Sensor Connector, Wiring, or perhaps the Sensor itself. That is in the "line" from the Condenser to Expansion Valve, located beside the Windshield Washer Filler Tube. Is that NEW as well?

If AFTER the "Pull"/Push/WOT/High RPM acceleration, the Blower function continues, and the Indicator Lights on A/C Control Panel all remain on, but you simply have NO refrigeration, (but cooling returns after "Reset" at idle), that suggests that the Refrigerant Pressure Sensor has signaled TOO HIGH Refrigerant Pressure, and IHKA/JBE has shut down Compressor Function, to avoid damage to the compressor.

That could be a "Bogus" signal, OR the system could be overcharged. HOW MUCH R-134a was added after evacuation of the "New System"? The entire charge after evacuation should ONLY be 20.8 OUNCES.

The Compressor function is NOT dependent upon vehicle speed, OR on "Pull" or Load, but ONLY engine RPM and Compressor Valve Activation. So you don't need to "Pull", just observe High Side Pressure at certain RPM.

In other words we're trying to see & RECORD the Refrigerant Pressure Signal Value (IF you have INPA/ISTA) at 2k RPM for 10 seconds, then 3, RPM for 10 seconds, then 4k RPM for 10 seconds, etc. You can probably do that safely in your driveway, in P/N. I would personally have heartburn doing 5k or more with NO Load. Of course if you don't have INPA/ISTA, you can simply monitor Manifold Gauge pressures at selected RPM, but THAT will NOT show you the Signal that IHKA/JBE Modules are receiving from the Sensor, and THAT signal is what is likely causing Compressor Valve "shutdown".

Don't dismiss the possibility of Refrigerant Over-charge. INPA allows you to read Static or Equilibrium Refrigerant Pressure after vehicle has sat for an hour or more, engine OFF. You can do the SAME with a Can Tap & Gauge connected to the Low Side, or with Manifold gauges. A HIGH Static reading suggests an Over-charge. Generally, Static pressure (HIGH & Low sides equal) should be approximately equal to Ambient F Temp. If Ambient Temp is 75F, Static Pressure should be ~ 75 PSIG. Pressure IS Temperature-Dependent. Same for Dynamic readings of High & Low side pressures with engine at idle compared with Pressure/ Temperature R-134a chart readings.

If you have the tools to diagnose, please let us know what you have, and your findings in the tests suggested above. Begin with the "Static" or "Equilibrium" Pressure check, where engine has been OFF for an hour or more. Report Pressure AND Ambient Temp, and we can suggest Next Steps. If you need any specific suggestions about INPA/ISTA use, let us know.
George

[haaken675]

Originally Posted by gbalthrop

First question that occurs to me: WHO installed "ENTIRELY brand new a/c System" and WHY? If NOT YOU, then ask installer. If YOU, get INPA or Manifold Gauges so you can properly diagnose it.

Most likely suspects are (1) Refrigerant Over-charge, or (2) Bad Refrigerant Pressure Sensor Connector, Wiring, or perhaps the Sensor itself. That is in the "line" from the Condenser to Expansion Valve, located beside the Windshield Washer Filler Tube. Is that NEW as well?

If AFTER the "Pull"/Push/WOT/High RPM acceleration, the Blower function continues, and the Indicator Lights on A/C Control Panel all remain on, but you simply have NO refrigeration, (but cooling returns after "Reset" at idle), that suggests that the Refrigerant Pressure Sensor has signaled TOO HIGH Refrigerant Pressure, and IHKA/JBE has shut down Compressor Function, to avoid damage to the compressor.

That could be a "Bogus" signal, OR the system could be overcharged. HOW MUCH R-134a was added after evacuation of the "New System"? The entire charge after evacuation should ONLY be 20.8 OUNCES.

The Compressor function is NOT dependent upon vehicle speed, OR on "Pull" or Load, but ONLY engine RPM and Compressor Valve Activation. So you don't need to "Pull", just observe High Side Pressure at certain RPM.

In other words we're trying to see & RECORD the Refrigerant Pressure Signal Value (IF you have INPA/ISTA) at 2k RPM for 10 seconds, then 3, RPM for 10 seconds, then 4k RPM for 10 seconds, etc. You can probably do that safely in your driveway, in P/N. I would personally have heartburn doing 5k or more with NO Load. Of course if you don't have INPA/ISTA, you can simply monitor Manifold Gauge pressures at selected RPM, but THAT will NOT show you the Signal that IHKA/JBE Modules are receiving from the Sensor, and THAT signal is what is likely causing Compressor Valve "shutdown".

Don't dismiss the possibility of Refrigerant Over-charge. INPA allows you to read Static or Equilibrium Refrigerant Pressure after vehicle has sat for an hour or more, engine OFF. You can do the SAME with a Can Tap & Gauge connected to the Low Side, or with Manifold gauges. A HIGH Static reading suggests an Over-charge. Generally, Static pressure (HIGH & Low sides equal) should be approximately equal to Ambient F Temp. If Ambient Temp is 75F, Static Pressure should be ~ 75 PSIG. Pressure IS Temperature-Dependent. Same for Dynamic readings of High & Low side pressures with engine at idle compared with Pressure/ Temperature R-134a chart readings.

If you have the tools to diagnose, please let us know what you have, and your findings in the tests suggested above. Begin with the "Static" or "Equilibrium" Pressure check, where engine has been OFF for an hour or more. Report Pressure AND Ambient Temp, and we can suggest Next Steps. If you need any specific suggestions about INPA/ISTA use, let us know.
George

I hadn't thought of an overpressure scenario, but that would seem to make sense due to how fast the compressor would be spinning at high rpms. I have been driving the car for a month or so since the system was replaced, and really only ever have seen this situation recently.

I replaced the entire system myself for a whole number of reasons. The car had been in a front end collision at some points in its sad life and the PO thought it was ok to JB weld the low pressure lines where there were clearly a crack or pinhole of some sort. The condenser needed replacement, and the dash had to come out for an evaporator as it was leaking after the new lines and condenser were replaced. I replaced the compressor for 2 reasons. 1) I didn't want there to be the possibility of any garbage in the compressor ruining the new evaporator and having to pull the dash apart again, and 2) When i put the line into the old compressor it shredded the o-ring and a small piece dropped in......

I did all the work myself with proper tools, vacuum pump, gauges, etc. It's possible i put a little too much refrigerant in, but all the pressures were looking good.

I do not have INPA, but I do have Protools. I wonder if i can see the pressures there somehow.

[gbalthrop]

Originally Posted by haaken675

... I did all the work myself with proper tools, vacuum pump, gauges, etc. It's possible i put a little too much refrigerant in, but all the pressures were looking good.
I do not have INPA, but I do have Protools. I wonder if i can see the pressures there somehow.

If you have Manifold Gauges, I would get a "Static/Equilibrium" Engine OFF reading first thing in the morning when Ambient temp lowest. Please post Pressure & Temp, and confirm High & Low sides same.

AFTER that static reading, since you have all the tools, and obviously know how to use them, you might also post your High & Low side Dynamic readings at idle, along with ambient temp when readings made. For those WITHOUT Temp/Pressure Chart, here is ONE Example:
https://www.acprocold.com/faq/r-134a...ressure-chart/

I haven't used ProTool, but from what I've heard about it, it can do most of what INPA can do. Using INPA, one would connect to the IHKA Module and read Live Data, in this case Refrigerant Pressure Sensor Value in bar units (5 bar = 72.5 PSIG / 1 bar = 14.5 PSIG). Attached to NEXT POST is an example INPA Screen that displays BOTH Refrigerant Pressure Sensor Value and Evaporator Temp Value on same screen, with other Temp Sensor Values.

So the Module receives that data, and the Data can be viewed as Live Data if properly queried by whatever Software you are using. Hope you can figure out HOW to do that (contact BG if you can't), and please post info here to help others with ProTool/ Diagnostic License.
George

[gbalthrop]

INPA > IHKA > F5 Status > F1 Analog Inputs ScreenPrint, as described in prior post.
George

[gbalthrop]

Originally Posted by haaken675

I hadn't thought of an overpressure scenario, but that would seem to make sense due to how fast the compressor would be spinning at high rpms. I have been driving the car for a month or so since the system was replaced, and really only ever have seen this situation recently...

Back in the Last Millennium, when Auto A/C and Big-bore V-8's were coming into vogue, Police Cruisers used to have a decal on the Dash that said something to the effect:

"Disengage Compressor Clutch BEFORE giving chase."

I don't recall seeing ANYTHING in reliable E9x Documentation (Owner's Manual, Bentley, ISTA) that suggests the Compressor Valve is AUTOMATICALLY made inactive at certain engine RPM.
ANYONE know of ANY such "Reliable" Documentation?

I regularly accelerate to 6k+ RPM in 1st and/or 2nd with N52K engine, (High RPM NOT sustained for 3 seconds or more). I have NEVER noted the Compressor Valve to De-activate. At least I've NEVER noticed momentary warming of air from vents.

I would modify the "Sixties Trooper" approach: "Hit SnowFlake BEFORE giving chase".

George

[haaken675]

Thankfully Protools can in fact look at the climate control info, including pressure. Unfortunately it looks like my gauges need replacing as the high pressure side wont seal properly and caused a bit of a mess in the engine bay. Probably not the worst thing in the world however as it does look like it might have been overcharged.

Its about 95 out today (car thinks it's 99),and sitting at somewhere around 4500 rpm the pressure was around 311. Will check again when cruising when my wife can hold the tablet. This is after losing more refrigerant then I would have wanted in a normal circumstance. Will report back.

Gbalthrop, thanks for pointing this out as a possibility. Might have taken me longer to come to this conclusion otherwise.

[gbalthrop]

If Protools can read Refrigerant Pressure Sensor signal (High side), AND Evaporator Temp, then you can use Protools values for High side, and use your manifold Gauge or Can Tap Gauge to monitor Low Side. I had a leak in my Manifold gauge High Side Adapter, but it was nothing more than the fact the the Quick Connect Adapter was NOT screwed on tightly to the Red Hose. May also have bad/missing O-ring.

Pressure/Temperature R-134a chart is meant to be used at idle RPM AFAIK. The ONLY reason I was suggesting testing at 2k, 3, or 4k was simply to get some data on the High Side Value at increased RPM. The main thing is: Does the Compressor Valve quit pumping at some Value from the Refrigerant Pressure Sensor Signal. ALSO, determining the correctness/ plausibility of that Pressure Signal as received by the JBE/IHKA Modules.

Hope you didn't lose too much Refrigeration Oil (PAG oil). The refrigerant alone would not "cause a mess", so anything wiped up by a paper towel is PAG Oil.

George

[haaken675]

Originally Posted by gbalthrop

If Protools can read Refrigerant Pressure Sensor signal (High side), AND Evaporator Temp, then you can use Protools values for High side, and use your manifold Gauge or Can Tap Gauge to monitor Low Side. I had a leak in my Manifold gauge High Side Adapter, but it was nothing more than the fact the the Quick Connect Adapter was NOT screwed on tightly to the Red Hose. May also have bad/missing O-ring.

Pressure/Temperature R-134a chart is meant to be used at idle RPM AFAIK. The ONLY reason I was suggesting testing at 2k, 3, or 4k was simply to get some data on the High Side Value at increased RPM. The main thing is: Does the Compressor Valve quit pumping at some Value from the Refrigerant Pressure Sensor Signal. ALSO, determining the correctness/ plausibility of that Pressure Signal as received by the JBE/IHKA Modules.

Hope you didn't lose too much Refrigeration Oil (PAG oil). The refrigerant alone would not "cause a mess", so anything wiped up by a paper towel is PAG Oil.

George

The mess was definitely the oil, but i used the UV dye oil so a lot of that mess is due to the Dye I think.

Didn't get a chance to measure while i was driving as I forgot the tablet, but I did manage to drive the car properly with no shut down of the a/c system. I'm going to call it a win so far.