Air con 1991 nsx

[1md.mandrake]

I have been having an on going problem with my air con, have finally been able to find someone who has been able to re-gas my car using a compatable gas to R12 but it hasn't fixed my problem, air con runs cold on first start up then gets back to natural air temp after 20 minutes or so. My guy feels that I probably have a problem with the expansion valve but cannot locate where it's positioned and how to get at it.
Your help would be much appreciated as air temp in London is un- seasonally high.

Thanks
MAN DRAKE

 

[davidf]

The expansion valve is mounted next to the evaporator. If you had to add Freon to your system, your problem goes beyond your expansion valve. If you wind up having to purchase an evaporator, the expansion valve comes with it.

 

[1md.mandrake]

Sorry if I sound dumb but where is the evaporator and how easy is it to get to ?
Thanks for your advice .
MAN DRAKE

 

[J KRIB]

It is behind the dash, I can't remember if you have to take the entire dash right out to access it but my gut tells me you might have to, if you are gonna tackle the job yourself buy some new 'O' rings for the evaporator fittings and do not reuse the old ones. Did you charge it with R134a?

 

[1md.mandrake]

Thanks
yes R134A plus PAO 48 oil, sounds like a terrible job!

 

[TomCat]

The expansion valve CAN be replaced from the front (spare tire) bay without pulling the dash.
Don't be too sure that it is the EV though.

It is a common "fall back" explanation...BUT after Acura (and my well trusted independent mechanic) said it was my expansion valve (and Acura wanted ~$1,600 to fix)...I changed it myself and that did not fix.
It turned out I had a blocked dryer ($100 fix)...so my recommendation is to diagnose and proceed methodically and not throw money/parts at it.

 

[1md.mandrake]

Thanks for that, will get back to my guy this morning, a really big help.

 

[davidf]

Anyone replacing an Evap/expansion valve ect. should at the same time replace the drier, especially if it's 20+ years old. It's cheap and relatively easy to do.

 

[nsxtasy]

And if you haven't already converted the A/C system on your 1991-1992 NSX to R-134a refrigerant, this would be a good time to do so. The upgrade kit is still available from dealers; the part number is 38020-SM4-A1AH and it costs around $60.

 

[farm180]

Good day everyone.

Been following this posting since my 92 AC seems to have lost a bit of cooling latley. I am not sure if its the AC unit or just the very hot weather we had the other week .

Davif, can you tell me what the drier is and where its in the car. i would like to start with that foward.

 

[Briank]

First thing to check is if the compressor clutch is on. Most nsx's dont have a very quiet compressor so you should be able to hear it when its compressing. A check of the condensor fans should be done when the cooling works and then fades out.

 

[davidf]

If you open the hood {front} and look straight down directly behind the bumper cover, you will see it. A silver canister with a site glass on top and 2 lines attached.

 

[TomCat]

Check for good/full R12/134a charge
Check for compressor operation.
Check for fans operating.
Try to trouble shoot...
Replacing dryer is relatively easy/cheap and MIGHT be a good place to start if all else reveals normal.

 

[J KRIB]

The expansion valve CAN be replaced from the front (spare tire) bay without pulling the dash.
Don't be too sure that it is the EV though.

It is a common "fall back" explanation...BUT after Acura (and my well trusted independent mechanic) said it was my expansion valve (and Acura wanted ~$1,600 to fix)...I changed it myself and that did not fix.
It turned out I had a blocked dryer ($100 fix)...so my recommendation is to diagnose and proceed methodically and not throw money/parts at it.

Is the expansion valve not threaded to the evaporator, I thought you needed to take the evaporator out to get to the expansion valve which meant pulling the HVAC box under the dash. The evaporator connections are accessible from the spare tire area so you can disconnect the lines going to the evaporator that is pretty much all you can do under the hood in regards to the evaporator. Did you take the blower motor box out in order to get access to it, just wondering incase I need to replace mine, I would prefer not having to pull the dash if mine fails down the road.

 

[TomCat]

Did you take the blower motor box out in order to get access to it, just wondering incase I need to replace mine, I would prefer not having to pull the dash if mine fails down the road.

Exactly!