2/93 A/C Mystery - Need Ideas and Help

[Gieser]

This is my first post and definately not my last. I have a very interesting problem. I replaced the following A/C equioment (all from Toyota)
1. A/C compressor and clutch
2. Evaporator
3. Expansion Valve
4. Dryer/Reciever
5. Codenser

Backed it all out, sucked out the air, then refilled it and it was COLD, got down to about 48 degrees . I drove off and parked it in the hot sun for about 2 hours. Started her up, turned on the A/C and it never went below 64 degrees and stayed around 65-70 . The next morning, it was about 54, but throughout the day, it really stayed aroud 65-70 again, which in 100 degrees does very little.

I thought maybe the fan clutch was not pulling enough air through the condensor, so I replaced the fan clutch (with generic - it took 3 to get it right), and that did not fix it .

The guages on high and low are readig steady, the high side is in range, but the low is reading about 350, but should be around 200. I also checked the sensor that allows heat to enter the system, and that was working correctly.

Does anyone have an idea of what would keep the temp coming out at 64-70 as opposed to the low 50's? I am really stumpped and would appreciate any ideas.

Thanks in advance,

Andrew

 

[-Spike-]

The temp of the air coming out of the vents is directly related to the temp of the air outside. First, the system will only cool so much, so if the air starts out hotter it ends up hotter. Second, if the condenser isn't cooling the refrigerant sufficiently, A/C performance will suffer. Two factors affect that; hot outside air and insufficient air flow across the condenser.

Do a search, this subject was touched on several times in the past few days.

-Spike

 

[RavenTai]

The guages on high and low are readig steady, the high side is in range, but the low is reading about 350, but should be around 200.

I hope that is the high side not the low that is reading about 350 PSI,

did you use R-12 or R134?
did you add oil or did the new parts coem pre oiled?

did you perge you gauge lines before filling?

is the new expansion vavle OEM?

what exactly are the pressures?

 

[Gieser]

I hope that is the high side not the low that is reading about 350 PSI,

did you use R-12 or R134?
did you add oil or did the new parts coem pre oiled?

did you perge you gauge lines before filling?

is the new expansion vavle OEM?

what exactly are the pressures?

R134 was used
Parts were pre oiled
The lines were perged
expansion was new OEM
High Pressure is 380
Low pressure is normal around 30

 

[Gieser]

Spike said: Two factors affect that; hot outside air and insufficient air flow across the condenser.

Does the fan clutch not have a lot to do with that? I other words, could a bad fan clutch be pulling to little air through the condenser?

 

[Bear80]

That would be the first place to look, but also how many 12oz cans did your system take?

 

[Gieser]

That would be the first place to look, but also how many 12oz cans did your system take?

Don't know exactly, had my guy I use purge it then fill it. they have emptied it twice and refilled it thinking it could be air or moisture.

 

[Bear80]

well if you had simi-pros do it then they probably know that it will take more freon charge when it is cooler outside. I usally run the water hose across the front to get the temps down. If you did it this way, the guage pressure will also come WAY down and it will take more freon charge. The pressure will also stay in the book range even after it takes more chrage and the water is stoped across the front. I've done several toyotas and found if you charge it on a hot day, it will take less freon, read correct and not cool vs. runing the water, or on a cold day, take more freon yet still read correct.

 

[Bear80]

Other than that, all I can suggest is that it is way overcharged on oil. BUT if you said it worked great at first then after you had it in the heat it didn't, I would guess back to what I just stated in the last post.

 

[Gieser]

Other than that, all I can suggest is that it is way overcharged on oil. BUT if you said it worked great at first then after you had it in the heat it didn't I would guess what I just stated in the last post.

It was cool in the AM. Never really got cool in the afternoon (when it gets really hot and humid). After not cooling, sometimes it will get cool again, but normally in the evening or early morning (when temps are cooler). It sort of does what it wants to from 60-75. It will start off sometimes very cold, but not always. You know how you can feel the air coming out, but the car never gets cool enough...that is what it is like.

 

[Bear80]

It sort of does what it wants to from 60-75.

What are you saying here?? MPH??

Sounds to me like an efficiency problem which points to low freon charge. You need to keep in mind that the guages tell you the system pressure and not necisarrily the freon charge.

You know I didn't even ask, was yours factory charged with r12 or r134?? That will also mean alot!

 

[97 FZJ80]

Why did you change out all the AC parts in the first place? Was it due to a compressor failure?

Based on the pressure readings, there is a clog in the system. Did you flush out the system?

 

[LX_TREME]

If it's R134 you just need 2 small cans and it's enough, just filled 'em couple weeks ago and blow cold air (freeze) even in the hot humid LA.And sometimes i need to turn it off due too cold inside

 

[Bear80]

Sorry, 2 cans is not enough. If it was factory charged with r134, you will take a full 3 12oz. cans.

 

[Gieser]

What are you saying here?? MPH??

Sorry, this was referring to temp.

 

[Gieser]

Why did you change out all the AC parts in the first place? Was it due to a compressor failure?

Based on the pressure readings, there is a clog in the system. Did you flush out the system?

The compressor went out, and the condenser was blocked, so, since I had to change those parts, I naturally changed the expansion valve and the receiver/dryer...while I was changing things, I decided to change the evaporator. I will ask them to see if they flushed the system.

 

[Gieser]

Sorry, 2 cans is not enough. If it was factory charged with r134, you will take a full 3 12oz. cans.

I am not sure it is about th3e amount. Like I said, sometimes it blows air in the lower 50's. I would expect if it were lower on R134, it would never really get that cold.

 

[Gieser]

Here is the exact amount of liquid and gas that was used when recharged

4.1 oz of liquid (oil)
1.76 oz of gas

 

[-Spike-]

1.76 oz of gas

That's about 28.24 oz too little, give or take 2 ounces.

could a bad fan clutch be pulling to little air through the condenser?

Yes. A good fan clutch can be pulling too little air across the condenser. Since you seem reluctant to do the search, here's a couple of links to make it easy for you: https://forum.ih8mud.com/showthread.php?t=51171 and https://forum.ih8mud.com/showthread.php?t=94653

-Spike

 

[Gieser]

Since you seem reluctant to do the search, here's a couple of links to make it easy for you:

I was not reluctant, I have been reading those all day long . I still believe the problem may be the new fan clutch we installed (number 4), so I ordered on from Toyota.