300ZX (Z32) Forums Dedicated to 90-96 ZCars otherwize known as the Z32's

AC problems.... help please

Old 05-08-2014, 02:06 PM
  #1  
Registered User
Thread Starter
 
Join Date: Apr 2014
Posts: 9
AC problems.... help please

I recently paid to have paid to have my system converted to r134a cause my ac was blowing warm air. After the conversion I still had warm air. The mechanic told me it my be my blender doors. After a little troubleshooting myself I've found my low side is ice cold(by the valve), I also found its cold by the expansion valve inside the AC unit, but then after that there is no coldness in the system.

My mechanic friend told me if I clamp the hoses by the firewall for the heater core that it would cut off the heater core and the air should go cold and that that would let me know if it was a blender door stuck or inop. I tried this and the air stays warm.

I'm leaning at a bad expansion valve but my friend told me if I had a bad EV that I would abnormal high and low pressures but the place that converted my system said my high and low pressures were good.

So please if someone could help it would be great cause Georgia is getting really hot right now... Thanks in advance.
Thomas Ward is offline  
Old 05-08-2014, 03:22 PM
  #2  
Registered User
 
PredatorZ's Avatar
 
Join Date: Apr 2011
Location: A Shady Tree in Boise
Posts: 1,032
better than a clamp

Clamping a hose will kink it and eventually cause a leak, many have installed a valve on the input side to the heater core, then all you have to do is open it for winter and close it when it warms back up. Go to your local hardware store, everything you need is in the plumbing dept.
The valve that normally turns off the hot water is located next to the heater core, usually operated by a cable from the dash controls. it is possible the cable came loose, either at the heater control, or the valve, on each end is a small snapping clamp that holds the control cable in place, if one popped loose it wouldn't open or close and it would feel pretty much normal.

Last edited by PredatorZ; 05-08-2014 at 03:23 PM. Reason: spelling
PredatorZ is offline  
Old 05-08-2014, 04:24 PM
  #3  
Registered User
 
zxguy1986's Avatar
 
Join Date: Aug 2013
Posts: 1,102
Also check your vacuum pump and hoses. That system operates the air distrib system and the air dampers behind your vents. All your hoses are OK and are correct diameters? See Thumper's guide at Vacuum Lines Also your FSM has major troubleshooting instructions for your A/C.

If push comes to shove, you can loop off the hot supply to the heater core for the summer and do it on the engine side of the firewall.

Do you know if you're getting cold refrigerant up to blower level? If so, getting cold air from your vents is probably a damper operation issue, my guess. Sticky damper. You might jog your dampers into working right, blower on, if you toggle the driver's side floor vent slide switch up and down a few times (it's in front of your right knee) and leave it in the down position. Works in my '86

Last edited by zxguy1986; 05-08-2014 at 04:40 PM.
zxguy1986 is offline  
Old 05-08-2014, 04:40 PM
  #4  
Registered User
Thread Starter
 
Join Date: Apr 2014
Posts: 9
So just to clarify when I clamped the hoses it didn't help so doing anything to limit the heater core shouldn't help my issue.

Is the condenser suppose to be cold? I haven't felt it to check. I know the hoses into the ac unit through the fire wall is super cold.

Is the Evaporator suppose to get cold?
Thomas Ward is offline  
Old 05-08-2014, 04:42 PM
  #5  
Registered User
 
zxguy1986's Avatar
 
Join Date: Aug 2013
Posts: 1,102
Yes, evap is cold if all valves are working.
zxguy1986 is offline  
Old 05-08-2014, 04:47 PM
  #6  
Registered User
Thread Starter
 
Join Date: Apr 2014
Posts: 9
Ok so took the panel off behind the glove box where the expansion valve is and the expansion valve is cold along with the large tube under it that wraps around the back side. however the evaporator isn't cold at all.
Thomas Ward is offline  
Old 05-08-2014, 05:18 PM
  #7  
Registered User
 
zxguy1986's Avatar
 
Join Date: Aug 2013
Posts: 1,102
According to my '86 FSM diag HA-9, the expansion valve controls the amount of refrig spray to the evap. If evap is not cold, the expansion valve is closed and delivering nothing. If your blower is on through that, you may have a bad/stuck expansion valve.

Last edited by zxguy1986; 05-08-2014 at 05:21 PM.
zxguy1986 is offline  
Old 05-17-2014, 10:22 AM
  #8  
Registered User
Thread Starter
 
Join Date: Apr 2014
Posts: 9
Update

Ok so after I ripped out my dash I replaced the expantion valve and gutted the throttle suction valve. The tsv was guts were corroded and stuck in place. After all that I took it to the shop had them flush and recharge. After all that my AC is now working!!!!!! I'm about 95% sure it was the tsv and not the expansion valve but I changed both while I was in there.
Thomas Ward is offline  
Old 05-17-2014, 10:57 AM
  #9  
Registered User
 
PredatorZ's Avatar
 
Join Date: Apr 2011
Location: A Shady Tree in Boise
Posts: 1,032
Nice work

Way to go Thomas !, now you can bask in the coolness of your hard work.
PredatorZ is offline  
Old 05-17-2014, 06:02 PM
  #10  
Registered User
 
zxguy1986's Avatar
 
Join Date: Aug 2013
Posts: 1,102
Aha. I predict you will survive another Georgia summer. Come back in the fall and we will re-do everything!
zxguy1986 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ZBspires
280ZX (S130) Forums
3
08-30-2013 07:33 AM
86z31
300ZX (Z31) Forums
1
08-16-2010 06:14 PM
turbo84z
300ZX (Z31) Forums
9
01-21-2008 02:26 PM
duowing
280ZX (S130) Forums
68
09-30-2006 08:26 AM
hondahunter
240Z, 260Z, 280Z (S30) Forums
8
03-18-2003 02:45 AM


Thread Tools
Search this Thread
Quick Reply: AC problems.... help please


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.