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I'm sure this has been mentioned before, but I couldn't find the correct key words....
My wife's 93 Z28 sucks to drive in the hot temps because as she accelerates, the AC shuts off until the throttle levels off. It does this even under slight acceleration. Today, the car sat in mid 90s temps for a few hours and got really toasty inside. Doing city driving didn't allow the car to cool off very well because the AC was cutting out at every light. How do I disable this? I know why it's there, but it's too sensitive and does not follow Red Planets idea of being able to go 0-60 in <5 seconds with the AC on!!
Are you saying the compressor shuts off or that the air does not blow out of the vents (but will blow out the defrost and floor)? If it is the latter, you have a vacuum leak issue.
The entire system shuts down. I was told that it was to give power back to the engine when it's needed. Someone could've been blowing smoke, but I don't know 4th gens. Once the speed levels off, or the acceleration is gradual enough, the AC gradually starts blowing again.
When highway cruising, the AC will blow fine at constant speeds, but shuts off when trying to pass. I don't think anything blows out the floor or the defrost at this point. Does this make sense?
The a/c compressor will shut off at WOT, but there is nothing that will cause the fan blower to stop. In the vacuum situation I already mentioned, it can seem like the fan blower stops (sometimes harder to tell when the engine is making more noise under acceleration).
It's as Rob says, you have a vacuum leak. The system is not shutting down, the vacuum actuated doors are changing position when you jump on it due to a leak. We all get one eventually. I'll put money on it being somewhere in the cabin.
I pulled the vacuum connector off at the AC control valve and put a hand vacuum pump on each color hose to find mine.
BTW is there a setting for the HVAC that does not seem to change? Like I had a problem with the feet position. It should have only come out the feet but it also came out defrost too. That's a dead give away you have a vacuum leak.
I had a chance to look into this a little over the weekend. While reading the "vacuum leak issue" tech article, it mentions that the actuators will default to defrost and floor when *not* enough vacuum is present. That, I knew, but will it change to defrost and floor when accelerating? What would be the best guess for repairing this? I am thinking the check valve might be an issue based on the internal actuators working most of the time. I really don't want to replace the colored vacuum hose setup in the dash. I was in there this weekend and heard a slight hissing sound at the control assembly valve, but I figured that was because it was just a simple assembly that hooked onto 2 stems loosely. The check valve is only $6, so easy fix there. I would assume that if it were the vacuum canister or the vacuum source hose, the actuators would not function properly at all. Any opinions?
It's going to do the same thing while accelerating, because that is a period of low vacuum. You need to fully test the vacuum hoses to be sure they are not leaking. It sounds like you have no reserve vacuum. Is 5 months not long enough to get them tested?
I pulled the check valve and tested for vacuum. Unfortunately, I needed to use lung power for all tests. The check valve appears to be working without any leaks. I created a vacuum at each nipple on the valve and sealed off the other two nipples. All three held suction until I let go. I also checked each vacuum line and all 3 held vacuum. The hose to the cannister required multiple breaths to evacuate, but once evacuated, it held.
I was reading some other info that stated to check vacuum going to the mode selector valve in each setting. I had full vacuum when the selector was "off", but every other setting sucked air. It seems that I have an issue inside the car. In this situation, with all settings sucking air, is it possible that all the actuators are bad? could the entire vacuum harness be bad?
I was reading some other info that stated to check vacuum going to the mode selector valve in each setting. I had full vacuum when the selector was "off", but every other setting sucked air. It seems that I have an issue inside the car. In this situation, with all settings sucking air, is it possible that all the actuators are bad? could the entire vacuum harness be bad?
Curious what you found out my issue now seems just like yours on my 1996RS convertible Camaro 3800 series V6
I’ve always known something was wrong when we bought it from my wife’s sister. It always lost the Dash Vent when I gave it any amount of gas it seems like🤔 always suspected a vacuum leak in the dash but now it seems to have gotten worse as I have nothing but defrost and floor vents working no matter what 😕 shame I just got the air conditioner charge system perfect and it was running cold the last month still is running cold just not at my face
I don’t think all the actuators could be bad at once impossible. I do think now my main vacuum to the mode selector isn’t working do you have a diagram how to take the dash apart to get to it?
I think you emailed me about this problem. Use this link to do some testing and see where you might have a vacuum issue. Don't start by tearing the dash apart.
OK thank you sir 😊👍🏻 “ I haven’t done any Dash ripping apart yet LOL “ I did see a video where someone got to the colored vacuum tubes underneath the glove box. Is that a good place to test for vacuum leaks? I spent most the day getting a good vacuum gauge and pump, I got the Harbor Freight one I don’t know if it’s good enough I hope. Here’s another thought I can’t remember what happens on these cars when you turn the HVAC control **** when the car isn’t running? etc. like key and run position but not running engine. I can’t remember, I think maybe it stays in the last default position of the dampeners? I don’t know you don’t think about those things when things are working LOL anyway it’s getting late thank you for answering me I’m new at this so thank you for taking it easy on me. Right now I noticed a crack in this device by the firewall
I take picture of it for you. I think it might be something to do with the check valve you all were talking about.
Thanks in advance for the warning, I have Monday and Tuesday I can get back to this, for now it looks like windows down again
And I will read everything you sent me
It’s fixed! Thank you so much shoebox! Using your troubleshooting steps you sent me it did turn out to be the vacuum check valve, I still have to buy one – as I used liquid electrical tape and a piece a super 33 electrical tape and it all came back online and it seems like when I accelerate it’s not dying as bad as it used to no telling how long that part has been bad probably since I’ve owned the car. All modes work, air is very cold. I did get to check when the car is off, engine I mean ,in the on position on the ignition, you really don’t get much mode selection it must be how older cars are 🤔 I guess it really needs that vacuum.
So glad I don’t have to open anything in the dash. Now to get that part it seems the part number you listed doesn’t seem to fit a 1995 or 1996 Camaro I don’t know why, maybe it’s discontinued. This is what GM parts Giant tells me in their generic car type verifier.
should I just go to the GM dealer maybe they still have the part. Thank you in advance and thanks again so much. Enjoy your Labor Day weekend.
05-23-2005, 07:23 PM
