A/C only working at idle
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Joined: Jun 2023
Posts: 66
Likes: 3
From: Orlando
A/C only working at idle
Need help! This is extremely weird. I have a 1993 base model coupe corvette with a LT1 motor. I had my ECM rebuilt and bought a new climate control module and my A/C only comes out cold at idle. When I begin driving the compressor goes off. Any idea why this would happen? What would be the solution to this situation? I greatly appreciate your help.
Vinny
Vinny
Racer
Joined: Oct 2023
Posts: 383
Likes: 123
From: St. Petersburg, FL
Have you checked the pressures when reving the engine ? Might just be low on refrigerant and when you rev the engine the pressure goes down and the low pressure switch shuts off the compressor.
Melting Slicks
Joined: May 2014
Posts: 2,894
Likes: 592
From: New Port Richey FL
Once you confirmed that the freon is correct, take a look at the TPS voltage is correct it should be around 0.5 volts when you start driving at speed the car may think you're flooring it and AC cuts out if the TPS isn't correct or failed
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Thread Starter
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Joined: Jun 2023
Posts: 66
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From: Orlando
The green light is solid and it does not flash. All is good. The clutch stays engaged when I rev the motor. I do have the denso. Just my luck! It is not more than 90 days old. I'll speak to the auto parts place about that. Good idea. My pressure read 200/30. We added a bit more just to see if anything would change. I don't believe the pressures are too high at this point.
I do remember not having enough in the past and getting the flashing green light. I'm going to change out the TPS today. I ordered it yesterday. Let's see what that does. If that does not work, i'm changing the coil. Thank you!
I do remember not having enough in the past and getting the flashing green light. I'm going to change out the TPS today. I ordered it yesterday. Let's see what that does. If that does not work, i'm changing the coil. Thank you!
Racer
Joined: Oct 2023
Posts: 383
Likes: 123
From: St. Petersburg, FL
The green light is solid and it does not flash. All is good. The clutch stays engaged when I rev the motor. I do have the denso. Just my luck! It is not more than 90 days old. I'll speak to the auto parts place about that. Good idea. My pressure read 200/30. We added a bit more just to see if anything would change. I don't believe the pressures are too high at this point.
I do remember not having enough in the past and getting the flashing green light. I'm going to change out the TPS today. I ordered it yesterday. Let's see what that does. If that does not work, i'm changing the coil. Thank you!
I do remember not having enough in the past and getting the flashing green light. I'm going to change out the TPS today. I ordered it yesterday. Let's see what that does. If that does not work, i'm changing the coil. Thank you!
Thread Starter
Advanced
Joined: Jun 2023
Posts: 66
Likes: 3
From: Orlando
I actually have r12 in my car. 134a never really worked for me. I live in Florida and it is just too hot. The car definitely stays cold when I rev the engine. I can hold it at 3 grand or 4 and it stay cold. As soon as I drive away and hit say 3rd gear, the air god warm which means the compressor is going off. it's driving me crazy. changing the TPS did nothing.
Thread Starter
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Joined: Jun 2023
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From: Orlando
Agreed. I don't have the equipment to check the pressure. My mobile mechanic will be here on wednesday. the is the soonest he can get to me which stinks. thank goodness it is cool out. he told me to take the positive cable off the battery to reset the car to see if that does anything. i'm going to try that. all of a sudden it just stopped working when it was great. working only at idle is so weird.
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Joined: Jun 2023
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From: Orlando
Yes. 100%. I'm not an expert mechanic but I do know a thing or two. I've changed most of the parts in the car. Diagnosing electrical stuff is definitely not my forte. Ever since I changed to R12, my AC is amazing. It never went warm like this and my compressor is maybe 90 days old. Brand new.
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
I actually have r12 in my car. 134a never really worked for me. I live in Florida and it is just too hot. The car definitely stays cold when I rev the engine. I can hold it at 3 grand or 4 and it stay cold. As soon as I drive away and hit say 3rd gear, the air god warm which means the compressor is going off. it's driving me crazy. changing the TPS did nothing.
Agreed. I don't have the equipment to check the pressure. My mobile mechanic will be here on wednesday. the is the soonest he can get to me which stinks. thank goodness it is cool out. he told me to take the positive cable off the battery to reset the car to see if that does anything. i'm going to try that. all of a sudden it just stopped working when it was great. working only at idle is so weird.
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Joined: Jun 2023
Posts: 66
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From: Orlando
This is interesting. I did it and came up with 00. I did what you said and it started at 73. I took it for a short ride because I had a 4pm meeting that I'm still on now. It went up to 79 and no further. I'm going to do it again to see if it jumps around. It seemed to go up from 73 to 79 slowly. After my meeting i'm going to jump on the highway and see if that number jumps over 120.
Cannot thank you enough for your feedback on this.
Cannot thank you enough for your feedback on this.