Ok, so when I got this car, the ac would work and then stop working. I had someone diagnose it and they said the compressor was bad. I finally got a used compressor from the junkyard when I did my h22a swap. The system was open for a couple weeks or so. I didn't realize at the time this was bad. I finished the swap and the system was back together after about 2 weeks. This was about a year ago.

Finally the other day I got around to bothering with the system. I went to autozone and did my own recharge. It emptied a can in and then didn't register anything on the cold side. I tried a new can then a new gauge. Nothing was working so I returned it all except for the can I emptied into the system. Keep in mind, there was no cold air blowing out at this time with the ac system on full blast. I figured it wouldn't work.

A few days later I was messing with my idle and had all accessories turned on and realized it was blowing cold air with the ac on. I was pretty happy but realized it would then turn itself off after about 30 minutes. Also, the air was cold but not really really cold. It was working to some extent though.

The other day I took it to my trusted mechanic that I have do work that I can not do. He evacuated it with a proper machine. Then he refilled it with oil and refrigerant. Then we started it up, it didn't blow cold air so he said it could be the dryer since he said it wasn't circulating as he was judging by looking at the window at the top of the dryer. I already have a dryer and expansion valve that I got from rockauto but hadn't need to put so I took it home and through the dryer in but not the valve. He then recharged it and again it wasn't blowing cold air. I then gave up and he told me I needed a new compressor. He showed me that the compressor clutch was working(engaged). He demonstrated on a used Denso that he had how the clutch works by way of putting his fingers in the holes and spinning the clutch and having me see the suction. So I figure ok I need a compressor now.

Later on that night I tried the ac and it's again blowing cold, this time really cold, however it, again, turns off after a few minutes of use. What happens when it works is I can hear the compressor turn on when I turn the ac on, I can then hear what appears to be maybe the expansion valve or something of the sort from the evaporator area behind the passenger side dash doing something when the compressor cycles on. Then at some point when the system stops blowing cold there is no such sound or activity from the evaporator area. The fans are still on, but I haven't checked to make sure the compressor is on, but I believe it is.

I, personally think that maybe the ac pressure switch might be bad and turn something off when the pressure builds up. When I tested the pressure switch after his last recharge of my system it has continuity. That's what I don't get why it wasn't blowing cold at that time.

 

AC pressure switch is unlikely the problem. It will turn the compressor off if it senses high or low pressure. That's only function.

Compressor may be warming up and clutch gap too large preventing compressor coil from pulling the clutch closed. You will need to access the compressor, release from mountings, and remove a shim behind clutch plate. It can be done in place w/o discharging, but would be easier if compressor is removed.

You can confirm this is problem by waiting to see compressor not engaging, and then rapping compressor clutch plate (careful!) w/ a stick. If it immediately engages and runs, excess clutch gap is confirmed.

good luck

 

I have read some posts you and the others have posted and suggested perhaps a clutch gap issue and they said no, but I think it's cause they don't really know about that. I will check the ac system again tomorrow(or later today lol) and when it finally stops blowing cold as usual I will first check if the compressor is still on and if not, I will give it a good whack.

If it turns on I will remove a shim as you suggested.

thanks

 

I have found in my Helms about removing shims in the Clutch inspection area. It says to measure the clearance between the pulley and the pressure plate all the way around.

It shows CLEARANCE: 0.5 +- 0.15 (0.020 +- 0.006 in)

I will try to get as close to that as possible. I am gonna include this for anyone else with the same issue as me.

 

Ok so it started blowing cold. When it finally stopped i pulled over and saw that the clutch was engaged and the compressor was on but it just wasnt blowing cold anymore. What could it be ? I would think if the compressor and/or clutch was bad it would never blow cold but it does and when it does blow cold its ice cold.

 

Only way to know whats going on is to hook up an AC manifold guage set and measure pressures when cooling is good and when it goes off.

Most likely possibility is a faulty expansion valve (opening too much or closing too much), probably opening too much since closing too much would likely cause pressure switch to disenage compressor when high side pressure goes too high.

good luck

 

Ok i wil get a set of gauges and take some readings and report back. Thanks

 

ok I finally got some pics taken.

Pictures by holmesnmanny - Photobucket

They go in order taken and start with 7 and 8 which were taken with the car off overnight with no ac used. However, they are not sorted in order. For some reason this site wouldn't let me upload pics so I used Photobucket instead. Then I start the car and take a picture each time the compressor cycles on and off. What appears to happen is the cold side starts to move down to 0. I believe image8 is with the compressor on then each successive picture goes compressor off, then compressor back on and so on.

Eventually the cold side goes down to 0 and I think this is when I start getting no cold air coming out, however the compressor is staying on at this time, it stays on all the time with no cold air coming out. Both fans always run as well.

 

Pictures suggest perhaps low charge or weak compressor causing low refrigerant flow rate.

When compressor is off (assumption here no annotation to indicate when compressor is running or off), low side goes to near zero (low flow rate passing expansion valve) and high side stays about the same.

When compressor is engaged, low side comes up to 10-25 psi and high side stays in range 125-150 psi. This will produce some cooling depending on air temp.

What was air temp when these readings were taken? This affects high side readings.

good luck

 

Sorry, TH. I shoulda been more clear. Those picture are in order picture number-wise ie. image7...image8...image9 but not sorted in order so if you scroll over em you should be able to see the image number.

What I did was I took the image7 and image8 before I started the car the first time. Then I started the car and in image9 should be with compressor on and engine on, then image10 would be when compressor cycled off after about 15 seconds or so, then after another 15 seconds the compressor would cycle back on and this should be image11 then I just keep alternating it. The cold air doesn't stop until the last pic or so when the low side is down to 0. At this time, the compressor just stays on along with the fans which always run when I turn the ac on.

When I just turn the ac on the ac blows ice cold. I would think if the compressor was bad it wouldn't blow cold at all ? I would like to just know for sure the compressor is bad because I have an expansion valve I can throw on it if the problem is just the expansion valve but a new compressor is $200 or so for a new Denso. I'd rather not buy one if I don't have to. My original compressor I had would do the same thing, blow cold for a while then stop blowing cold then after waiting and starting it back up it would blow cold again, so I'm inclined to think the problem is not the second junkyard compressor I pulled but I'm interested in what you think.