M.Bonanni Posted January 10, 2016 Share Posted January 10, 2016 (edited) Hello everyone! Sorry for the general "noob" questions, but I am definitely a noob when it comes to the S30. Even after scouring through the Haynes manual I am still not 100% confident knowing everything that's missing so I figured I would turn to you all! The car is a '78 280Z with factory air conditioning that wasn't working when I bought it. Being that I live in Vegas, I am really trying to get it working again before summer. Without fully knowing what I am looking at and/or for all I can tell that's missing used to be here... EDIT: After my initial post and a very helpful link to the FSM below I can see now that the circled area is missing a few things. On the topic of the A/C system, it is missing the magnet valve F.I.C.D. and the vacuum tank as far as I can tell. This discovery helped but left me with more unanswered questions I had originally... 1. It's my understanding that all this valve does is keep the car from stalling at idle while the A/C is on correct? If that's the case then shouldn't my A/C system still theoretically work so long as I keep the car from stalling? Or is there more to this valve than I am realizing? 2. As for the vacuum tank, I am assuming that can be replaced with any aftermarket vacuum tank as well correct? Is there an aftermarket work around for the valve? 3. I also noticed that the fusible links that are supposed to be there aren't and been simply bypassed by just directly connecting everything. Would this have any effect? I wouldn't think so but maybe it's not a coincidence that the only two things on this car that have been messed with are right next to each other. Again, thanks in advance for helping me with my learning curve on this new (to me) project! Edited January 11, 2016 by M.Bonanni Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 10, 2016 Share Posted January 10, 2016 Use the Factory manual. AC. http://www.nicoclub.com/FSM/280z/ Quote Link to comment Share on other sites More sharing options...
M.Bonanni Posted January 10, 2016 Author Share Posted January 10, 2016 Use the Factory manual. AC. http://www.nicoclub.com/FSM/280z/ Awesome! Thanks! I will start digging into it now! Quote Link to comment Share on other sites More sharing options...
M.Bonanni Posted January 11, 2016 Author Share Posted January 11, 2016 Updated the original post with some new questions after my FSM findings. Thanks again NewZed! Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 11, 2016 Share Posted January 11, 2016 1. It's my understanding that all this valve does is keep the car from stalling at idle while the A/C is on correct? If that's the case then shouldn't my A/C system still theoretically work so long as I keep the car from stalling? Or is there more to this valve than I am realizing? 2. As for the vacuum tank, I am assuming that can be replaced with any aftermarket vacuum tank as well correct? Is there an aftermarket work around for the valve? 3. I also noticed that the fusible links that are supposed to be there aren't and been simply bypassed by just directly connecting everything. Would this have any effect? I wouldn't think so but maybe it's not a coincidence that the only two things on this car that have been messed with are right next to each other. No problem. Study the diagrams that show what the different control settings do. The magnet valve (solenoid) just allows vacuum to be applied to the selector valve. The selector valve controls many devices. So you could run a vacuum line directly to the selector valve but the various devices would open and close with engine vacuum if you don't have the vacuum bottle (vacuum reservoir). Wwithout the FICD (fast idle control device) the compressor load will drop your engine RPM when the AC is on. You could work around it with the idle screw but it's convenient to have. Does the system even produce cold air? You might be getting ahead of yourself. The old systems use R12 which can be hard to find. Might be why the PO ripped all of the control system out. Check the parts inside also, like the vacuum cock, and the hoses to the doors. People tend to go crazy when they decide they hate something. If they're not there you might have a big project ahead. And you should check the fusible link connections just to save your car, in general. If they've been bypassed and you get a short you'll melt a bunch of wiring and life will suck. Quote Link to comment Share on other sites More sharing options...
M.Bonanni Posted January 11, 2016 Author Share Posted January 11, 2016 No problem. Study the diagrams that show what the different control settings do. The magnet valve (solenoid) just allows vacuum to be applied to the selector valve. The selector valve controls many devices. So you could run a vacuum line directly to the selector valve but the various devices would open and close with engine vacuum if you don't have the vacuum bottle (vacuum reservoir). Wwithout the FICD (fast idle control device) the compressor load will drop your engine RPM when the AC is on. You could work around it with the idle screw but it's convenient to have. Does the system even produce cold air? You might be getting ahead of yourself. The old systems use R12 which can be hard to find. Might be why the PO ripped all of the control system out. Check the parts inside also, like the vacuum cock, and the hoses to the doors. People tend to go crazy when they decide they hate something. If they're not there you might have a big project ahead. And you should check the fusible link connections just to save your car, in general. If they've been bypassed and you get a short you'll melt a bunch of wiring and life will suck. Thanks again! Yes the fusible links have made their way to the top of the list now that I know they're not there. As for the A/C, I will look into the rest of it as you suggested and keep my fingers crossed. I will continue searching for an FICD as well. I am assuming whatever it is wont be an easy fix as this car has lived its whole life in Las Vegas and there isn't any one of us that wouldn't do everything humanly possible to retain A/C haha. Quote Link to comment Share on other sites More sharing options...
cgsheen Posted January 11, 2016 Share Posted January 11, 2016 (edited) Lucky for us, the "default" for the HVAC system is essentially "A/C Mode". With no vacuum bottle, and the vacuum solenoids (magnet valves) non-operational, the system defaults to recirculation of cabin air and blowing out the dash vents - perfect for A/C operation. Not good for heat or defrost, but perfect for A/C. The vacuum system is needed to switch modes - to open the door for fresh air from the cowl rather than recirc cabin air, to close the dash vents and direct air to the floor outlets or defrost vents, to redirect air from evap core (A/C) to heater core. And to run the FICD - which is probably more for engine fan speed (more air over condenser core and radiator at idle while the compressor is running) than "oh no, the engine might stall"... That actually describes my 260Z. Factory A/C, no vacuum bottle, no vacuum solenoids (magnet valves), no FICD, no vacuum tubing from the engine bay into the cockpit (that was all removed from this frame before I got it), heater core leaked within weeks of putting it on the road so no heater. A/C works stellar though and there are about 3 days a year when I wish I had a heater core and functioning HVAC vacuum system... I accumulated the parts years ago, but I've never installed them. Las Vegas probably gets a little cooler than Phoenix and I'm an Idaho Boy that never got used to the heat. I'll take 60 degrees any day... I don't have a problem with the stock compressor pulling down the idle too far, but I'm motor swapped and not using a stock engine management system. It'll drop from 800 RPM to 650-700 PRM with the compressor engaged. I will admit, on 110 degree days here, I could use a fast idle and a shroud that fit my 240Z style radiator (early 260...) for condenser air flow while I'm not moving... Enjoy your A/C and work at restoring the rest at your leisure. The bottle and solenoids are fairly straightforward, as is the FICD. The vacuum tubing under the dash is slightly more complicated but the FSM shows you how all that should be routed. Don't be confused by all the different "mode" drawings, just follow the routing diagram and you should be fine. Edited January 11, 2016 by cgsheen Quote Link to comment Share on other sites More sharing options...
M.Bonanni Posted January 11, 2016 Author Share Posted January 11, 2016 Lucky for us, the "default" for the HVAC system is essentially "A/C Mode". With no vacuum bottle, and the vacuum solenoids (magnet valves) non-operational, the system defaults to recirculation of cabin air and blowing out the dash vents - perfect for A/C operation. Not good for heat or defrost, but perfect for A/C. The vacuum system is needed to switch modes - to open the door for fresh air from the cowl rather than recirc cabin air, to close the dash vents and direct air to the floor outlets or defrost vents, to redirect air from evap core (A/C) to heater core. And to run the FICD - which is probably more for engine fan speed (more air over condenser core and radiator at idle while the compressor is running) than "oh no, the engine might stall"... That actually describes my 260Z. Factory A/C, no vacuum bottle, no vacuum solenoids (magnet valves), no FICD, no vacuum tubing from the engine bay into the cockpit (that was all removed from this frame before I got it), heater core leaked within weeks of putting it on the road so no heater. A/C works stellar though and there are about 3 days a year when I wish I had a heater core and functioning HVAC vacuum system... I accumulated the parts years ago, but I've never installed them. Las Vegas probably gets a little cooler than Phoenix and I'm an Idaho Boy that never got used to the heat. I'll take 60 degrees any day... I don't have a problem with the stock compressor pulling down the idle too far, but I'm motor swapped and not using a stock engine management system. It'll drop from 800 RPM to 650-700 PRM with the compressor engaged. I will admit, on 110 degree days here, I could use a fast idle and a shroud that fit my 240Z style radiator (early 260...) for condenser air flow while I'm not moving... Enjoy your A/C and work at restoring the rest at your leisure. The bottle and solenoids are fairly straightforward, as is the FICD. The vacuum tubing under the dash is slightly more complicated but the FSM shows you how all that should be routed. Don't be confused by all the different "mode" drawings, just follow the routing diagram and you should be fine. Thanks for the clarification! The FSM and Haynes manuals aren't the easiest to understand so thank you for spelling it out better for me! I have no prior experience or knowledge with how A/C systems work so you just saved me hours of research. Still have a lot of diagnosing to do before I draw any conclusions as to what it will actually take to get everything working properly again but one can only hope that all it needs is a re-charge and a new FICD setup to work like factory again! Quote Link to comment Share on other sites More sharing options...
88dangerdan Posted January 11, 2016 Share Posted January 11, 2016 Started reading your threads (feeling a little guilty) and thought this might help. And "yes" is the answer from your pm. Get that taken care of here this week. I'll send you a pm here shortly. Daniel Quote Link to comment Share on other sites More sharing options...
M.Bonanni Posted January 11, 2016 Author Share Posted January 11, 2016 Started reading your threads (feeling a little guilty) and thought this might help. 20160111_130644.jpg And "yes" is the answer from your pm. Get that taken care of here this week. I'll send you a pm here shortly. Daniel No need to feel guilty and thanks for the photo! It certainly does help and I may have found another oddity with my setup thanks go this photo. My receiver dryer is on the other side of the engine bay. Maybe a difference between my '78 and your model year? Or maybe more work has been done to my A/C system than I thought. Quote Link to comment Share on other sites More sharing options...
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