A/C Check '94 w/134a

[POS Racing]

OK so I tried Miatamoto's coolie pressure gauge and this is what I get.

Would the A/C be colder if the gauge was closer to 45? Or is this a good place for it to be?

It blows cold but it seems as if it could be colder, but I don't have a lot of experience working with A/C systems.

Cool page on how to mess with the a/c - http://www.xanga.com/item.aspx?user=...&uid=213551321

TIA

[Tim the Teacher]

Is the a/c on when you get that reading?

[POS Racing]

Is the a/c on when you get that reading?

Yep!

[Tim the Teacher]

How many cans of freon did you add on the low side when you charged it?

[gabkwong]

I don't know much about a/c ether ... but I let mine at the same area of the gauge out of fear of over pressurize the system and damage the compressor, or worse, explosion! I am like you, thinking that it can be colder. I hope Stevan can give us some clue to the clueless!

[POS Racing]

Haven't added any freon this is my baseline reading.

[Tim the Teacher]

From what I've read 1 pound 3 ounces should be enough to fill but you don't know how much is in right now. Does your condensor cycle constantly (every 30-45 seconds) or does it take 3 to 4 minutes to cycle?

You might want to ask these dude...http://acsource.net/acforum/viewforum.php?f=1

ETA: I found this as well

http://www.miata.net/garage/r134.html

[Tim the Teacher]

I found this chart that may help...
http://www.chillers.com/PT%20charts%...frigerants.htm

[Keifersmith]

Can you judge anything using the sight glass? I added R-12 to my 90 and 91 last summer using it since I didn't have a gauge. My system was low on freon so I could see bubbles flowing past the sight glass. Added R-12 until the fluid was flowing clear (i.e. no bubbles). Maybe not the most accurate but it gets cold now.

Keith

[cam76034]

The only way to know for sure is to evacuate the system and recharge with the correct amount of refrigerant. IIRC Miata only holds 21 oz. of 134, which is less than 2 cans. I bought a bunch last year from Big Lots for $4 a can, not a big investment for making sure you have the correct charge. Rent the vacuum pump from AZ, evacuate the system and recharge with the correct amount.

Don't buy any with the stop leak stuff.

[onething]

Simple thing to do is check ambient temperature and then put the thermometer in the AC vent. Twenty degrees cooler is all you can get IIRC.

My little bro, the AC dude, is supposed to call me later today. I'll verify it with him. I also have a coolie temp gauge designed to do this if you want to use it.

[sammm]

Was '95 the first year for R134 in Miatae?

[cam76034]

Simple thing to do is check ambient temperature and then put the thermometer in the AC vent. Twenty degrees cooler is all you can get IIRC.

My little bro, the AC dude, is supposed to call me later today. I'll verify it with him. I also have a coolie temp gauge designed to do this if you want to use it.

I've gotten 40degrees lower than outside temps at the vent.

Was '95 the first year for R134 in Miatae?

94

[POS Racing]

OK so I tried Miatamoto's coolie pressure gauge and this is what I get.

Would the A/C be colder if the gauge was closer to 45? Or is this a good place for it to be?

Lets go back to my original question does anyone have first hand experience on upping the pressure a touch while keeping in the safe range. Will it make any difference or am I best to leave it alone??

[cam76034]

Lets go back to my original question does anyone have first hand experience on upping the pressure a touch while keeping in the safe range. Will it make any difference or am I best to leave it alone??

You can try adding some and see if your vent temps improve any. But with two cans you can do it the right way and not worry about overcharging it. You won't be able to do that with the gauge you've got.

[cam76034]

Put your $200 deposit down at AZ, get the vacuum pump and a couple cans of 134 and I'll swing by with my gauges sometime this weekend and charge it up right.

[POS Racing]

The system is full now and works.

It is possibly a pound or so low on Freon.

So why would emptying it, then pulling a vaccum, and then refilling it with new 134a make any difference??

I'm thinking I don't want your help.

[cam76034]

The system is full now and works.

It is possibly a pound or so low on Freon.

So why would emptying it, then pulling a vaccum, and then refilling it with new 134a make any difference??

I'm thinking I don't want your help.

Let me put it another way. How can a system that holds 1.5 pounds be

possibly a pound or so low on Freon.

and still be

The system is full now

?

It's either full or it isn't. If it isn't then adding freon on top of an unknown quantity is nothing but guesswork, when doing it the right way is a matter of one extra can of refrigerant.

[onething]

POS, I know a guy in Burleson you would like and he's single right now