86 Climate Control Battle
08-13-2014, 01:11 PM
#1
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Thread Starter
Join Date: Feb 2014
Location: Bryant, Arkansas
Posts: 24
86 Climate Control Battle
Hello everyone,
This is an update on my battle with my 86 NA 2+2 deemed "Katrina" 's Automatic climate control to work (story at the bottom on the name) The symptoms of the issue were when i bought the car back in January all the air conditioner would do is blow hot air out of the defroster no mater what button is pushed on the control unit, with the exception of the fan speed.
I quickly figured out the water valve that controls the water to the heater core remained open. That valve if supplied with vacuum will actuate correctly so my next stop was the solenoid valve on the vacuum tank that is behind the passenger headlight i pulled that valve off and applied power to it and it will click i still need to test if the clicking is the valve opening and closing. Following the vacuum line from the vacuum tank through the firewall it T's and one goes to the passenger side of the car to a couple solenoid valves, the other goes to the driver side and in to a very intimidating bank of valves that supplies vacuum to the motors and bellows that operate the air doors inside of the heater core box. I was losing vacuum somewhere in that mess of lines. We finally decided to remove the heater core box so that we could get a better look at what was going on behind it. Once we had it removed i started testing lines and found that both of the vacuum motors had tears in rubber. I took the larger of the two up to school and made a 3-d model and had it printed off on a 3-d printer. The model turned out very well and probably would have worked but we couldn't find any rubber thin enough to work like the original so using a paint brush and some Shoe Goo i was able to seal the cracks and get them to work properly. While i had the box out i replaced all of the lines and drew a diagram of where they went since it is very confusing to look at. We then put everything back in to find that nothing had changed so we started trouble shooting by shorting the plug under the dash in the passenger wheel well. Back tracking a little we tried this before the pulled the dash all of the other craziness ensued, and none of the air doors would open when it cycled through. after all this work the door would now open and close like they are supposed to. This is where things start getting a little weird when you turn the car on the blows hot air out of the defrosters but when you short those lines even for a split second it fixes the problem. But when you turn the car off and back on again you have to short those contacts again. From what i understand that the computer in the control unit if it senses a problem it will go to "safe mode" which is heat out of the defroster. I am missing the part that goes in the headliner with the little fan so it may be sensing that is gone and when you short those lines it clears the error, almost like it goes through a self check on start up.
I then tried to drive it from my dads house to my house about a 75 mile trip i made it half way and the water temp pegged the gauge at 270 degrees so i stopped let it cool refilled it and fixed a leak on the line from the radiator cap to the overflow tank tried to continue and only made it about 5 miles when the water temp started to rise rapidly i then borrowed a friends car hauler and dragged it back to my dads where he started looking and the radiator looks pretty bad so we are going to pull it this weekend and probably send it to be refurbished.
I am not sure if these two are connected yet but when i figure something out ill post again. It was the hottest day that i have tried to drive the car and it was at interstate speeds so it could be just a coincidence that the old beat up radiator couldn't cool it well enough. I have pictures of the heater core which before i pulled it out i couldn't find any good pictures to look at, The drawing i made of where the vacuum lines went, the vacuum motor i printed off with the 3-d printer, and a over all picture of my baby who is quickly wearing on my nerves. in my album ill leave a link at the end of this post to those pictures.
Story on the name Katrina
I bought this car January 1 2014 from a car dealer in Fayetteville Arkansas for 1500 dollars. I was looking for a cheap fun car to learn to drive a stick. I then drove it home to Little Rock Arkansas (first time i have ever driven a stick needless to say it was a little jerky). I drove it as i bought it for a month or so, being that it was cold it didnt really matter that all it would do is blow hot air but once it started to warm up it got uncomfortable. During this time she was a little scary to drive. she kinda had a mind of her own and got angry if you didn't let her go where she wanted to go, which i can only assume she was really curious about what was at the bottom of a few ditches. This is the first sports car i have ever owned much less driven so i figured sports car were supposed to be exciting to drive and feel like they are trying to kill you, and she did not disappoint. But after i started doing some maintenance it all became clear, She was trying to kill me. The back brake pads were non existent, the tires on the front where so far out of line the outside edge of the tires had 50 to 60% tread while the inside edge was down to the metal banding. One back tire was bald down to the metal banding, and the other was new. There where 3 different sized tires on the car none of which where the correct size for the car. and the yayhoo before me at put the rear passenger sway bar on backwards which makes a god awful rattling. after we found all of this I got the Car fax for the car and found that the last time it was sold was in a suburb of Baton Rouge in 2005 which is conveniently about the time Hurricane Katrina came through. After my wife who hates the car found out this she started calling her Katrina.
ZDriver.com - Mikey8907's Album: 1986 300zx NA 2+2
This is an update on my battle with my 86 NA 2+2 deemed "Katrina" 's Automatic climate control to work (story at the bottom on the name) The symptoms of the issue were when i bought the car back in January all the air conditioner would do is blow hot air out of the defroster no mater what button is pushed on the control unit, with the exception of the fan speed.
I quickly figured out the water valve that controls the water to the heater core remained open. That valve if supplied with vacuum will actuate correctly so my next stop was the solenoid valve on the vacuum tank that is behind the passenger headlight i pulled that valve off and applied power to it and it will click i still need to test if the clicking is the valve opening and closing. Following the vacuum line from the vacuum tank through the firewall it T's and one goes to the passenger side of the car to a couple solenoid valves, the other goes to the driver side and in to a very intimidating bank of valves that supplies vacuum to the motors and bellows that operate the air doors inside of the heater core box. I was losing vacuum somewhere in that mess of lines. We finally decided to remove the heater core box so that we could get a better look at what was going on behind it. Once we had it removed i started testing lines and found that both of the vacuum motors had tears in rubber. I took the larger of the two up to school and made a 3-d model and had it printed off on a 3-d printer. The model turned out very well and probably would have worked but we couldn't find any rubber thin enough to work like the original so using a paint brush and some Shoe Goo i was able to seal the cracks and get them to work properly. While i had the box out i replaced all of the lines and drew a diagram of where they went since it is very confusing to look at. We then put everything back in to find that nothing had changed so we started trouble shooting by shorting the plug under the dash in the passenger wheel well. Back tracking a little we tried this before the pulled the dash all of the other craziness ensued, and none of the air doors would open when it cycled through. after all this work the door would now open and close like they are supposed to. This is where things start getting a little weird when you turn the car on the blows hot air out of the defrosters but when you short those lines even for a split second it fixes the problem. But when you turn the car off and back on again you have to short those contacts again. From what i understand that the computer in the control unit if it senses a problem it will go to "safe mode" which is heat out of the defroster. I am missing the part that goes in the headliner with the little fan so it may be sensing that is gone and when you short those lines it clears the error, almost like it goes through a self check on start up.
I then tried to drive it from my dads house to my house about a 75 mile trip i made it half way and the water temp pegged the gauge at 270 degrees so i stopped let it cool refilled it and fixed a leak on the line from the radiator cap to the overflow tank tried to continue and only made it about 5 miles when the water temp started to rise rapidly i then borrowed a friends car hauler and dragged it back to my dads where he started looking and the radiator looks pretty bad so we are going to pull it this weekend and probably send it to be refurbished.
I am not sure if these two are connected yet but when i figure something out ill post again. It was the hottest day that i have tried to drive the car and it was at interstate speeds so it could be just a coincidence that the old beat up radiator couldn't cool it well enough. I have pictures of the heater core which before i pulled it out i couldn't find any good pictures to look at, The drawing i made of where the vacuum lines went, the vacuum motor i printed off with the 3-d printer, and a over all picture of my baby who is quickly wearing on my nerves. in my album ill leave a link at the end of this post to those pictures.
Story on the name Katrina
I bought this car January 1 2014 from a car dealer in Fayetteville Arkansas for 1500 dollars. I was looking for a cheap fun car to learn to drive a stick. I then drove it home to Little Rock Arkansas (first time i have ever driven a stick needless to say it was a little jerky). I drove it as i bought it for a month or so, being that it was cold it didnt really matter that all it would do is blow hot air but once it started to warm up it got uncomfortable. During this time she was a little scary to drive. she kinda had a mind of her own and got angry if you didn't let her go where she wanted to go, which i can only assume she was really curious about what was at the bottom of a few ditches. This is the first sports car i have ever owned much less driven so i figured sports car were supposed to be exciting to drive and feel like they are trying to kill you, and she did not disappoint. But after i started doing some maintenance it all became clear, She was trying to kill me. The back brake pads were non existent, the tires on the front where so far out of line the outside edge of the tires had 50 to 60% tread while the inside edge was down to the metal banding. One back tire was bald down to the metal banding, and the other was new. There where 3 different sized tires on the car none of which where the correct size for the car. and the yayhoo before me at put the rear passenger sway bar on backwards which makes a god awful rattling. after we found all of this I got the Car fax for the car and found that the last time it was sold was in a suburb of Baton Rouge in 2005 which is conveniently about the time Hurricane Katrina came through. After my wife who hates the car found out this she started calling her Katrina.
ZDriver.com - Mikey8907's Album: 1986 300zx NA 2+2
08-13-2014, 02:25 PM
#2
Registered User
Join Date: Aug 2013
Posts: 1,103
Welcome back.
I don't remember whether we sent you to this posting Vacuum Lines for help with the vacuum lines. Good guide and good advice.
Sounds like you are doing a lot of catch-up maintenance work that was not done by previous owners. Your Z model has been/is so reliable that it tends to lull owners into a sense that it will always run well if they just leave it alone. They never check anything and let small issues grow into bigger ones.
I take it that your Z was not underwater during or after Katrina because I doubt that her electronics would still be working. So you were lucky on that one.
Keep us informed and keep up the good work. Your Z is worth it and you will feel terrific when it is finally running and working the way you want. Most of us have been where you are now and most of us kept on plugging. BTW, she looks great in your photo.
I don't remember whether we sent you to this posting Vacuum Lines for help with the vacuum lines. Good guide and good advice.
Sounds like you are doing a lot of catch-up maintenance work that was not done by previous owners. Your Z model has been/is so reliable that it tends to lull owners into a sense that it will always run well if they just leave it alone. They never check anything and let small issues grow into bigger ones.
I take it that your Z was not underwater during or after Katrina because I doubt that her electronics would still be working. So you were lucky on that one.
Keep us informed and keep up the good work. Your Z is worth it and you will feel terrific when it is finally running and working the way you want. Most of us have been where you are now and most of us kept on plugging. BTW, she looks great in your photo.
Last edited by zxguy1986; 08-13-2014 at 02:32 PM.
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