A/C not as cold as it should be
07-23-2010, 12:55 PM
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A/C not as cold as it should be I got my car out of storage down here in Phoenix and the A/C wasnt working. A guy I know has all the gauges and vacuum to mess with it so he tried pressurizing the system then vacuuming it down. Both times it held pressure.
We added freon until the low side pressure was alittle over 30psi and the high side around 300 psi.
The A/C works now, it just isnt super cold. My friend said he thought the condenser might be full of dirt/dust, as it was sitting outside where it probably saw a couple dust storms.
Does anyone know what exact pressures the LT1 system should have at the high/low side? Or what temp the air should be at the vent?
We added freon until the low side pressure was alittle over 30psi and the high side around 300 psi.
The A/C works now, it just isnt super cold. My friend said he thought the condenser might be full of dirt/dust, as it was sitting outside where it probably saw a couple dust storms.
Does anyone know what exact pressures the LT1 system should have at the high/low side? Or what temp the air should be at the vent?
07-23-2010, 01:04 PM
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07-23-2010, 01:15 PM
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Damn, i forgot about Shoebox...dont i feel stupid. Thanks LSWHO.
While I'm asking dumb questions, the car also dosent like to idle after driving with the A/C on. If you pull up to a stop light it drops down to about 500 RPMs and sputters like crazy. If you just sit for awhile holding the RPMs to about 1500, if you let off it will idle at around 800 RPM with the A/C on, but when the compressor kicks on it drops pretty low for a second.
Is this a tuning issue? It idles fine without the A/C on. Should I try drilling out the little hole in the bottom of the throttle body for more airflow?
While I'm asking dumb questions, the car also dosent like to idle after driving with the A/C on. If you pull up to a stop light it drops down to about 500 RPMs and sputters like crazy. If you just sit for awhile holding the RPMs to about 1500, if you let off it will idle at around 800 RPM with the A/C on, but when the compressor kicks on it drops pretty low for a second.
Is this a tuning issue? It idles fine without the A/C on. Should I try drilling out the little hole in the bottom of the throttle body for more airflow?
07-23-2010, 02:48 PM
#4
Damn, i forgot about Shoebox...dont i feel stupid. Thanks LSWHO.
While I'm asking dumb questions, the car also dosent like to idle after driving with the A/C on. If you pull up to a stop light it drops down to about 500 RPMs and sputters like crazy. If you just sit for awhile holding the RPMs to about 1500, if you let off it will idle at around 800 RPM with the A/C on, but when the compressor kicks on it drops pretty low for a second.
Is this a tuning issue? It idles fine without the A/C on. Should I try drilling out the little hole in the bottom of the throttle body for more airflow?
While I'm asking dumb questions, the car also dosent like to idle after driving with the A/C on. If you pull up to a stop light it drops down to about 500 RPMs and sputters like crazy. If you just sit for awhile holding the RPMs to about 1500, if you let off it will idle at around 800 RPM with the A/C on, but when the compressor kicks on it drops pretty low for a second.
Is this a tuning issue? It idles fine without the A/C on. Should I try drilling out the little hole in the bottom of the throttle body for more airflow?
07-23-2010, 06:24 PM
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Well I checked the vent air temp with my laser thermometer and it got down to 55*. I guess thats doing pretty well for an ambient temp of 110* outside.
07-23-2010, 06:32 PM
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sounds like you dont have enough freon in it 30 psi is kind of low it should circulate between 60 and 40 psi on the low pressure side and you really need an air conditioning machine to properly fill it up so you know exactly how many pounds your putting into the system
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07-23-2010, 08:45 PM
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300 on the high side isn't bad if ambient is 100+, which certainly wouldn't be unusual in Phoenix this time of year.
Don't try to correlate high and low sides based on pressure, doesn't work.
Don't try to correlate high and low sides based on pressure, doesn't work.
07-23-2010, 08:46 PM
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07-23-2010, 09:17 PM
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What are you questioning?
With 20% humidity, the high side will run about 290# in a 110 degree environment...sure sounds like Phoenix in mid-summer to me. If you have anything but refrigerant in the system (like a bit of air), pressure on the high side will easily exceed 300#.
As to my other statment...high side pressure and low side pressure are almost completely independent of each other, always have been and always will be, assuming the system is in some sort of reasonable running condition.
With 20% humidity, the high side will run about 290# in a 110 degree environment...sure sounds like Phoenix in mid-summer to me. If you have anything but refrigerant in the system (like a bit of air), pressure on the high side will easily exceed 300#.
As to my other statment...high side pressure and low side pressure are almost completely independent of each other, always have been and always will be, assuming the system is in some sort of reasonable running condition.
07-23-2010, 10:27 PM
#11
What are you questioning?
With 20% humidity, the high side will run about 290# in a 110 degree environment...sure sounds like Phoenix in mid-summer to me. If you have anything but refrigerant in the system (like a bit of air), pressure on the high side will easily exceed 300#.
As to my other statment...high side pressure and low side pressure are almost completely independent of each other, always have been and always will be, assuming the system is in some sort of reasonable running condition.
With 20% humidity, the high side will run about 290# in a 110 degree environment...sure sounds like Phoenix in mid-summer to me. If you have anything but refrigerant in the system (like a bit of air), pressure on the high side will easily exceed 300#.
As to my other statment...high side pressure and low side pressure are almost completely independent of each other, always have been and always will be, assuming the system is in some sort of reasonable running condition.
Low side at 30 psi is right if hi side is around 215. Hi side 300 and low side 30 is indicating a problem, as anyone who had ever diagnosed an a/c system properly would know.
07-23-2010, 10:36 PM
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Anyone who has spent any time troubleshooting A/C systems would know that low side problems don't affect the high side, and high side problems don't affect the low side. You're grossly misinterpreting the P/T chart. I've spent approximately 30 years professionally diagnosing A/C systems of all types...how about you?
07-23-2010, 10:50 PM
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Anyone who has spent any time troubleshooting A/C systems would know that low side problems don't affect the high side, and high side problems don't affect the low side. You're grossly misinterpreting the P/T chart. I've spent approximately 30 years professionally diagnosing A/C systems of all types...how about you?
07-23-2010, 11:24 PM
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Well, you better get back to the books then because I have been doing it for 20 years and you are completely and totally wrong. In a system like an LT1 F body has, hi and low side pressures are always and forever dependent on one another. Anyone who thinks otherwise has absolutely no understanding of how the system operates.
07-24-2010, 09:29 AM
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Well, "I" know next to nothing about A/C systems but, have heard that you can still have small leaks even though the quick pressure test before you fill with the machine passes. Are you SURE there aren't any leaks? Tried using the dye? Have you compared that temp reading you have to any other F-bodies? I've never thought of doing that but, I've always thought my AC was not cold enough. I'd be interested to know what temp the average LT1 F-body puts out. I always just assumed its not as cool as I want due to the insaine amount of glass on letting the sunlight heat the car up on the dash and in in the back. Just my thoughts.
07-26-2010, 01:28 PM
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Jumped in the car today and the AC wasnt working at all...back to the drawing board I guess.
I dont think it was working as good as it should have, I drove it for about an hour last saturday and I had to keep it on full blast the whole time and it still didnt really cool the cabin down all that well. Granted this was in 105* sunny weather but any other car I ride in, you have to turn the AC down after 20 minutes or so or you get too damn cold.
I was thinking about changing the orifice tube and drier...has anyone seen this orifice tube before? http://www.autozone.com/autozone/par..._122490_0_4365
Its $43 and says its an upgrade to stock. Worth trying?
I dont think it was working as good as it should have, I drove it for about an hour last saturday and I had to keep it on full blast the whole time and it still didnt really cool the cabin down all that well. Granted this was in 105* sunny weather but any other car I ride in, you have to turn the AC down after 20 minutes or so or you get too damn cold.
I was thinking about changing the orifice tube and drier...has anyone seen this orifice tube before? http://www.autozone.com/autozone/par..._122490_0_4365
Its $43 and says its an upgrade to stock. Worth trying?
07-26-2010, 07:36 PM
#18
Jumped in the car today and the AC wasnt working at all...back to the drawing board I guess.
I dont think it was working as good as it should have, I drove it for about an hour last saturday and I had to keep it on full blast the whole time and it still didnt really cool the cabin down all that well. Granted this was in 105* sunny weather but any other car I ride in, you have to turn the AC down after 20 minutes or so or you get too damn cold.
I was thinking about changing the orifice tube and drier...has anyone seen this orifice tube before? http://www.autozone.com/autozone/par..._122490_0_4365
Its $43 and says its an upgrade to stock. Worth trying?
I dont think it was working as good as it should have, I drove it for about an hour last saturday and I had to keep it on full blast the whole time and it still didnt really cool the cabin down all that well. Granted this was in 105* sunny weather but any other car I ride in, you have to turn the AC down after 20 minutes or so or you get too damn cold.
I was thinking about changing the orifice tube and drier...has anyone seen this orifice tube before? http://www.autozone.com/autozone/par..._122490_0_4365
Its $43 and says its an upgrade to stock. Worth trying?
I do not think that is where the problem lies. You most likely have a fairly large leak in addition to some condenser cooling issue. Check radiator cooling fans, chin spoiler, airflow path obstructions (trash bag stuck between radiator and condenser?) and recharge with UV leak detector dye.