Does 10 degrees make this much difference ?

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I should add I could not find a good ac shop and I am in Hawaii. Started doing all my own ac work. It was the expansion valve. Replaced and works great since. Expansion valve is some labor to replace as cooling box needs to come out. 92 not to bad
 
I should add if your expansion valve is clogged you will have very high pressure on your high port and very low on the low port. The ac is charged at low port. So high risk of overcharging if you do not have high and low gages attached that will indicate a clogged expansion valve
 
I think you said your compressor turns on and off a lot. Not sure if you have a high pressure ac cut out switch but if you do. That would point to clogged expansion valve. I think you also have a 92. Apparently does have a high and low pressure ac switch Make sure the wiring to these is making good contact as shop may have jarred them while doing work
 
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FJ80HI said:
I should add I could not find a good ac shop and I am in Hawaii. Started doing all my own ac work. It was the expansion valve. Replaced and works great since. Expansion valve is some labor to replace as cooling box needs to come out. 92 not to bad
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Appreciate it. I am making a list from all the helpful suggestions here.compressor not turning off and on a lot - just kicks on like it should when I push the AC button.
 
Tim Herald said:
Appreciate it. I am making a list from all the helpful suggestions here.compressor not turning off and on a lot - just kicks on like it should when I push the AC button.
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Got it. On my 92 the compressor would turn but after 10 minutes it would still turn but no cool. I think what would happen if the car sat for hours. The expansion valve would clear. Then re clog after running. The expansion valve has an extremely small hole that can easily clog. Something like a deteriorating ac hose debris could clog
 
If your compressor is staying on. Then with a 92. You are either low on refrigerant, clogged expansion valve, clogged fins on your condenser, or your filter/dryer clogged (unlikely), or compressor shot (probably unlikely as it would make a lot of noise). One other things to check. Is the compressor actually turning? I currently have an exterra and the electric clutch switches on but the clutch is shot. Do your hear the compressor actually load up? Your rig also has what is called an ac amplifier. The computer controls for the ac. All inputs go into this unit. However if your compressor is in fact spinning. The amp is probably good
 
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Tim H: Below are two threads I started back in the day. Note my ac has been working fine ever since replacing the expansion valve. A few years back I also had to replace the original ac compressor as the clutch burnt out.

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Thread 'AC Cools then Stops Cooling'

On my 91 FJ80 the ac works for 10 mins then stops cooling. Everything keeps running (the fan and compressor). I have verified refer is charged to specs. After the car sits for several hours the ac will work again- for about 10 mins then stop blowing cold air. I did have an ac shop look at it. They verified the charge and the ac worked while at the shop. The shop says the compressor is noisy and say it should be replaced. I am not sure this is the problem. The compressor is spinning (I was thinking may be an ac clutch problem- but that looks to be ok). I am thinking maybe the...
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Thread 'AC Compressor Short Cycles'

My 1991 FJ80 was starting to blow warm air. Got the 134a recharge kit and proceeded to fill with two cans to get pressure where gage says it should be. After filling the compressor now runs for 10 seconds and shuts off, it will come on after about 30 seconds then shut off after 10 seconds- this will continue. The ac will blow cold air when compressor is running. Did I over fill the system? I know there is a low pressure refrigerent cut out switch, some wiring diagrams indicate this is a dual low and high pressure switch. Could the high press switch be cutting out compressor? I plan...
 
FJ80HI said:
Tim H: Below are two threads I started back in the day. Note my ac has been working fine ever since replacing the expansion valve. A few years back I also had to replace the original ac compressor as the clutch burnt out.

F

Thread 'AC Cools then Stops Cooling'

On my 91 FJ80 the ac works for 10 mins then stops cooling. Everything keeps running (the fan and compressor). I have verified refer is charged to specs. After the car sits for several hours the ac will work again- for about 10 mins then stop blowing cold air. I did have an ac shop look at it. They verified the charge and the ac worked while at the shop. The shop says the compressor is noisy and say it should be replaced. I am not sure this is the problem. The compressor is spinning (I was thinking may be an ac clutch problem- but that looks to be ok). I am thinking maybe the...
F

Thread 'AC Compressor Short Cycles'

My 1991 FJ80 was starting to blow warm air. Got the 134a recharge kit and proceeded to fill with two cans to get pressure where gage says it should be. After filling the compressor now runs for 10 seconds and shuts off, it will come on after about 30 seconds then shut off after 10 seconds- this will continue. The ac will blow cold air when compressor is running. Did I over fill the system? I know there is a low pressure refrigerent cut out switch, some wiring diagrams indicate this is a dual low and high pressure switch. Could the high press switch be cutting out compressor? I plan...
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Appreciate it. I’ll read through them
 
So have done some more observations and kept up with them through the week. Before was just going off memory
When it was in the 50’s outside- the air really blows cold. At 68-70 blows cool enough to be comfortable. At 81 outside - I used a thermometer this afternoon and it’s blowing 71-72 when running 20-40mph. At idle it’s 75-76 out the vents - and driving 40-60, it was at 73-75. I have a new fan clutch- the compressor seems to be working as it should, but the system just can’t keep up when things get very warm. Reading a bunch more has me thinking it may just be low on 134a? Thoughts ? I am going to do a temp reading on the vent temp in the morning when it is cool outside, and it’s supposed to drop into the 40’s tomorrow afternoon. So will do then also.

I can get in my normal (non LC specialty shop) first thing in the morning and was really considering having them just fill her up with 134a just in case- add dye to check leaks- and hope that fixes things. The truck came from FL, so I am sure the AC was used a lot, and these are the first warm temps we have dealt with on a half regular basis since I got it. Just trying to get it fixed asap as we planned to take it on a bit of an excursion next weekend. I am definitely over my head as far as working on it- and my son who is a shade tree mechanic is gone in a trip for 10 days.

Any input is appreciated…
 
this YT video shows the replacement of the heater control valve, but I just wanted to show you the control cable from your HVAC control slider inside the cab (circled in red). See if you can separate this cable from the heater control valve, then rotate the valve with your fingers to see if that makes a big difference. It probably won't but at least you'll know the valve is all the way closed during A/C activation.

heater control valve


Next thing is to hook an a/c manifold gauge to your system, then do some objective analysis.
a/c manifold gauge hookup


1774559129826.webp
 
alia176 said:
this YT video shows the replacement of the heater control valve, but I just wanted to show you the control cable from your HVAC control slider inside the cab (circled in red). See if you can separate this cable from the heater control valve, then rotate the valve with your fingers to see if that makes a big difference. It probably won't but at least you'll know the valve is all the way closed during A/C activation.

heater control valve


Next thing is to hook an a/c manifold gauge to your system, then do some objective analysis.
a/c manifold gauge hookup


View attachment 4110080
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All new hoses, clamps and pretty sure the valve is new- but the cable is working properly anyway.
 
Definitely low on refrigerant after checking pressures. Had it tested and filled and blowing much colder. It’s not hot out and won’t be until next Tuesday - so will see if this cured it.
 
Marvelicious said:
Low on refrigerant right after the shop checked it out? 🤔
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Man I don’t know. So much has happened last couple of weeks, I don’t know what’s up or down with what was done or not at this point. When it went to shop, the issue was thermostat and no heat-That 100% fixed. I get back and it gets warm and air was failing. I know hoses, valves and wiring were issues as well, so not really blaming them as it was cold out, they probably turned air on and it blew cold- and thought it was OK. Then when it got 80 out, the AC was way weak. Heck when it is 80 next week it still may not work. A lot of variables and trial and error right now. I do know my system hasn’t been properly converted for 134a, and that will be an ongoing issue, but not dumping 2 grand into a total AC overhaul just yet. There was an aux fan on condenser they took off as they thought it was probably doing more harm than good as it wasn’t wired properly (when we couldn’t get up to temp for heat). If I keep having AC problems, will probably try putting that back on properly as well.
 
This is why I started doing my own ac. I got gages and a vac pump. Work on all 5 of my cars from Range Rover sport BMW 318 xterra frontier Nissan 240sx Toyota pick up and the mighty LC. Ac is not that hard but it is tedious and you could get eye damage if a hose blows off thing to do is find a good shop to discharge and pull vacuum on your ac. You will need to hold vacuum and vac also removes air and water from the system. If the system cannot hold vac you know you have a leak. Potentially you are low on 134 or you may have air in the system. Both would affect the efficiency. Also. As others mentioned pull the cable of the hot water valve and make sure it is fully closed. Maybe cable not adjusted. AC shop should charge less than 200 to pull vac and charge
 
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Fyi my 92 lc was converted. Only thing changed was dryer filter. I had a shop convert my r12 90 240sx and all they changed was filter dryer. You do not need that electric fan for your ac condenser. Keep it simple. If you bring your rig to Hawaii I work on it. The other thing. Unless you replace your entire ac system. Which would be expensive. You will have some minor loss of 134a. Just plan on buying a 12$ can and charge it yourself once a year. Buy at Walmart orally or auto zone with a fill hose add 30$
 
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FJ80HI said:
Fyi my 92 lc was converted. Only thing changed was dryer filter. I had a shop convert my r12 90 240sx and all they changed was filter dryer. You do not need that electric fan for your ac condenser. Keep it simple. If you bring your rig to Hawaii I work on it. The other thing. Unless you replace your entire ac system. Which would be expensive. You will have some minor loss of 134a. Just plan on buying a 12$ can and charge it yourself once a year. Buy at Walmart orally or auto zone with a fill hose add 30$
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Well the recharge seems to have done the trick. It’s been 80 for a couple of days and it’s blowing good and cold.

If I have to drop a can of 134a in once or twice a year and it stays like this, I’ll be just fine.
 
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Tim Herald said:
Well the recharge seems to have done the trick. It’s been 80 for a couple of days and it’s blowing good and cold.

If I have to drop a can of 134a in once or twice a year and it stays like this, I’ll be just fine.
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Some refill cans come with uv die. And you can buy the uv light. Try auto zone. If you want to locate any leaks
 
Tim Herald said:
Yup planned on that.
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If you find the leak do not under any circumstance use the r134 can with stop leak. It will plug your expansion valve. I learned from experience. Expansion valve labor intensive to replace along with full vac and charge. Fix the leak properly. Never use a can that says with stop leak. Read can carefully. You can buy a can with only 134a. That is what you want. Walmart and auto zone sell
 
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