Jump to content
HybridZ

heating and A/C problems


espo280zx

Recommended Posts

its not of extreme improtants right now, but my heat and A/C doesnt work in my 280zx. I was thinking heater core, maybe a relay. My windows roll down so thats why its not important right now, but if I am forced to drvie this through the winter, (which i DO NOT want to do cause of the rust it has) im going to need heat and defrost. I just dont want to go out and spend the little money i have on a heater core or this and that which might not be the problem. Anything else i should be looking towards as far a the heat and things that dont work? Or am I just asking a stupid question?

Link to comment
Share on other sites

  • 1 month later...

I have the same problem, I just disregard it for now (socal weather). However my system does work to some extent, the fan motor cuts on but no heat, AC "forget bout it", got's no belt on the pump, so whatever.

 

I would like to hear any suggestions on making my heater work correctly, it would help with defrost issues later on in the rain. Like I mentioned above the thing works (yes the plumbing from the motor to the core and back to the motor is fine) just not kicking out any heat, never had. I thought maybe it was the H-core but I didnt get any leaks in the cabin(so I am told with Z cars). H-fan clicks on when engaged, its evan blowing through the ducts.

 

Since I have had cars with no working AC but the heater works fine, I disregarded the fact that the AC pump was not engaged with a drive belt (76 firebird, I dismantaled the AC pump out the car but heater worked fine). any ideas on the matter would be helpful.

 

 

82 280zx coupe l28 all stock, no mods to the engine.

Link to comment
Share on other sites

  • 4 weeks later...

I think I have a small leak in the H core due to the sweet smell and the windshield fogging up almost immediately when I turn it on and never going away until I wipe it away. Is the heater core a hard replace once I get the front radio piece out or do I need to take off the entire front dash to get to it? Any recommendations on the supplier for the H core? I also recently had the A/C charged with R-12 and it doesn't seem like it's doing anything with cooling. The A/C lines don't have any temp difference in them. Do I have a leak and lost the R-12 or do I have too much oil in it or do I have a bad part? I replaced the condensor, drier, and had new lines made for the SR20 compressor.

Link to comment
Share on other sites

I also recently had the A/C charged with R-12 and it doesn't seem like it's doing anything with cooling. The A/C lines don't have any temp difference in them. Do I have a leak and lost the R-12 or do I have too much oil in it or do I have a bad part? I replaced the condensor, drier, and had new lines made for the SR20 compressor.

Quickie test: turn the A/C on, then look at the pulley. If the belt is going around but the front of the pulley isn't spinning, there's something wrong with the clutch or its control circuit. If it is spinning, there are still possibilities other than a leak - a bad TXV or strainer, for example. Is the belt installed and tension properly set?

 

Assumption check: did you have the system evacuated or just charged? Your worries about a leak are making me suspicious on that count.

Link to comment
Share on other sites

Belt is good, clutch is engaging, I asked to have it evacuated but suspect it was not. Since there are few R-12 servicing shops here these days, how will R-134 work in the Z and would I have to get one of those crazy mineral spirits trapping tools to get all that stuff out? Sight glass shows intermittent bubbles.

Link to comment
Share on other sites

For further diagnosis you really want a manifold gauge set. They're reasonably cheap (e.g. manifold, hoses) and, along with a stem thermometer, comprise the basic diagnostic toolkit for MVAC systems. Couple of test leads, a test light, and a FSM, and you can pretty much test anything [A/C-related] on a Z.

 

Well, and a vacuum gauge if you have the automatic climate controls. It's usually easier to have someone else do the work though, especially with R-12 as most people don't have a 609 certificate.

 

 

Anyway, R134a works tolerably well in about every application I've seen, OEM or retrofit. The biggest problem I've observed in, again, every application, is that it doesn't work well at all at idle. Kick it into neutral and run it up to ~1200 RPM and it's usually cold again.

 

If you retrofit, get as much of the old oil out as possible, flush the condensor and evaporator (at a minimum) and replace the receiver/drier. R-12 oil doesn't react well at all with R-134a and its oils. Replace every O-ring you can find, and consider a new TXV so you don't have to do that later on.

Link to comment
Share on other sites

  • 3 weeks later...

Ducts may be blocked (vent or inlet), heater core may be blocked, blend doors may be frozen in an odd configuration (it's always odd, for some reason), motor may not actually be turning the squirrel cage....

 

Your best bet would probably be to 1) download a 1975 FSM (XenonS30), and 2) check in the S30 forum. I'd guess from various comments floating around the 'net that you might want to focus your attention on the blower.

Link to comment
Share on other sites

Wow, I finally finished the heater core swap and it works great all over again. I should have taken pictures because I almost had the entire front part of my car out on the inside to do it. I was hoping after taking off the dash that I would be able swing the center box out over the frame, but it was too deep of a box. So I had to pull the fan box and A/C box to then slide the heater box over and under the frame. The A/C lines were empty, meaning I have a good leak somewhere. I'll get to that later, but my next job is going to be finding and fixing the vibration I have in one of the wheels. Thanks for the tips and good luck with your heater fixes.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...