2G: A/C guru's please help

[1995silvergst]

Wow two shops frustrated and have no anserws. I have taken my 96 eclipse gst to a shop for a/c repair. They have replaced the compressor, expansion valve, condensor, drier and evaporator. They flushed the system and sent it to another shop to also be flushed on a better machine after the second compressor was replaced to ensure it was clean. The old drier came apart, they said and sent the silica beads through the whole system, thats why I needed all new parts. The problem is now, when they recharge the system, at idle it cools when rpm is raised the low pressure was going into vacuum and high was popping the safety valve at 550 psi and blows warm. The third expansion valve they put in with the third compressor was an OEM mitsu unit, and now the low is 30 but the high is still through the roof and pops the saftey valve. They have checked the voltage on the output of the accu also and it checks out at 12volt, as well as the relays working properly IE: the fans do come on when max a/c is on and the engine idles up as it should. Please help they are on the third compressor and drier and going on the third week, any info would be appreciated.

[92AWDTalonTSI]

Remove the A/C. Roll your windows down and cruise.

[blackrosenova40]

If your high side is reaching 550 psi with the fan actually on then your radiator, condensor and or front mount cooler fins are plugged causing poor airflow for your fan. Or something is plugged somewhere in the system which you should check the entire system with a temp gun to find the restriction.

[1995silvergst]

Thanks blackrosenova40 for the info, no front mount yet bone stock for now. I will let them know to check the radiator, although it has not been over heating at all, even when at idle for a long time parked, fans kick on and cool it down but maybe the flow of fans is not correct. I truley am stumped and so are they, everything test out good with the exception of the high side pressure . I am not sure what exactly the ecu controles when it comes to the a/c maybe its there. 92AWDTalonTSI that is not an option in FL, funny but hot 92 yesterday heat index of 99 not to mention the fog from 100% humidity when it rains here every other day .

[blackrosenova40]

Wait I just noticed you said your low side is going into vacuum. Your low side should never go into vacuum. How is it cooling in your car? If it stay into vacuum for long periods of time it should be pretty dang cool in the car, which is good but if it gets too cold the evaporator can actually start to freeze up and could cause your situation.

I dont know about 2g's a/c but with an expansion valve system there should be a thermo probe in the evaporator to make sure it isnt freezing. If it does get close to freeze point it will shut the a/c compressor clutch off to prevent the evaporator from freezing.

[1995silvergst]

It was infact going into vacuum with the first expantion valve, however when the Mitsu ex valve was put in it has corrected that. The air was indeed cool 55 deg but when the throttle is pushed it iwas 70+deg out of the vents. And the high pressure valve pops with a few minutes of running above idle speed.

[redyute1]

It seems that the condenser isn't cooling the freon efficiently,try this,go home ran the ac and hose down the condenser while she runs,if the high side stays within 2 - 250 while hosing it down with cold tap water then condenser needs to be rreplaced

[BIRDCLAWTSi]

It sounds like an overcharge. The high side shouldnt go over 250, Can you see the compressor kick on? I would evacuate it, Vacuum it, And put in about a pound and watch for the compressor to come on. I dont know how they do/did it, But it sounds like they just kept putting freon in hoping it would work. Too much is just as bad as too little. A/c is a very simple system, There are only a few variables. You replaced the reciever drier and the expansion valve, Along with the condensor and compressor. I am guessing the lines are new too. You stated the electrical side is good. You can jump the compressor if you have to as well, to get it working.

[92AWDTalonTSI]

I used to live in Florida (Born in Ft. Myers Lived in Cape Coral). I know what you mean about the humidity. Sweating as soon as you walk out of your house. But then I had a Datsun and an Isuzu Trooper. With no A/C. It's not that bad. But I live in Illinois now. And for the past 7 years. I like it better here.

[1995silvergst]

Thanks for the suggestions keep them coming. redyute1 I will have them try running cold water over the condenser today although it is new but may have a clog, good way to check. BIRDCLAWTSi if Im not mistaken the system calls for 24.69-26.10 ounces of R134a and 5.7-6.4 ounces of compressor oil, I will double check what they put in and them try reducing it a little. The lines are not new they are reused, but have been flushed twice, could they be it as well?

[IHeartMyHonda]

from ASE master tech and IMACA certified AC tech: sounds like an overcharge. your high side pressures should never be that high. look at your low side line coming from the evaporator. does it have condensation on it? if it does, that means that your having a change of state happening later than its supposed to, and its indicative of an overcharge. some techs will assume that if an ac system isnt working right, a little more refrigerant will fix it, when infact, a 10% overcharge can be as bad as a 50% undercharge.

[redyute1]

Originally Posted by 1995silvergst

Thanks for the suggestions keep them coming. redyute1 I will have them try running cold water over the condenser today although it is new but may have a clog, good way to check. ?

Overlooked where you said the condenser was replaced,if it is new then it should be fine

[dsm8883]

Pressure's are not a good way to diagnose a ac system!!! temperature is the best way to check a ac system. check the inlet and outlet temperatures on the condenser and evaporator. You prob a restriction some were. A lot of new car's only have one service port so you have to use temperatures to check the system. Make sure the car has the perfect charge and good working fan's before checking it.

[1995silvergst]

Thanks again to all for the replies, I stopped by the shop today and asked the questions posted here. They charged and vacuumed the system now 12 times with all parts they have replaced each time with 25oz, they measured the oil out at 5.5oz. The lines are warm on the high and cool on the low. It cools fine at idle but is still pressurizing the high side too high when accelerated. Today they will be testing and replacing the dual pressure switch because he says it is not controlling the fans properly. Not sure if this is right or not, I thought that switch only controlled compressor cut on and off. Please anymore ideas?

*Update* I had a call from the shop last night saying they found a short in the fan wiring. The short is preventing the fans from high speed operation and though both are coming on they are only on in low causing the condenser to heat up and over pressurize. They tested this by using water over the condenser first then a large shop fan while at idle and under throttle. The ac cooled and pressures were perfect. Today they will chase the short and re-wire if needed the fans hopefully fixing the high pressure popping and fan speed problems.

[1995silvergst]

*Update* the shop has chased the shorts in the fans and now has them working properly they say. The end of the ac lines that attach to the compressor had to be rebuilt when they first took the bad compressor out, and when they sent this off to be done they say the company did not rebuild it with the refrigerant temp switch back in as they should. They are assuming this is part of why the last two compressors would not operate correctly . Now we are about to enter the fourth week they have had the car and we are waiting on this switch to diagnose if it helps control fan speed, and compressor pressures to normal, or if there is another piece not checking out. I will post again when I find out more from them. Please let me know if this sounds right someone, I am not familiar with the ac system enough to know what sensors and switches do what.

[1995silvergst]

Ok, well the shops have givin up, they said that they cannot figure out the problem, and have said that as far as they can tell there is an electrical prob somewhere. They have the car wired correctly, now that they fixed the hack job done previously by someone.And now suspect that the ecm is bad because there is no power to the relays or switches that control the compressor. The problem is the same that the high pressure side spikes and still causes the compressor to shut off when the rpm are raised. At idle it still cools correctly and the other electronics (fans) still work fine. Is there any way the ecm could cause this, the compressor not shutting off? I am now forced to see if the dealer has an appt open tomorrow and if I can get squeezed in. Please if anyone knows or has ideas I could use them. I did however manage to talk them down from 2800 to 1500 on the bill which covered the parts and help me allot.

[1995silvergst]

Well I took the car to the dealer Saturday and come to find out the compressor the shop put in, while it is a new or newly remanufactured compressor it is not the correct one. The one installed did not have a freon temp switch in the compressor manifold and they instead tried to wire the compressor to make it work. Now 1585.00 for the dealer to replace the compressor, clutch, pigtail to the compressor and labor to see. If of course the first shop did not damage the ecu, accu and relays when hard wiring the compressor the first time. The parts are due in Thursday and I will post again to see what the dealer finds next.

[chico904]

Originally Posted by 1995silvergst

Well I took the car to the dealer Saturday and come to find out the compressor the shop put in, while it is a new or newly remanufactured compressor it is not the correct one. The one installed did not have a freon temp switch in the compressor manifold and they instead tried to wire the compressor to make it work. Now 1585.00 for the dealer to replace the compressor, clutch, pigtail to the compressor and labor to see. If of course the first shop did not damage the ecu, accu and relays when hard wiring the compressor the first time. The parts are due in Thursday and I will post again to see what the dealer finds next.

Yeah, make sure the AC compressor you get is for a 95-96 turbo eclipse or a 95-97 turbo talon only. I had the same problem when I bought a compressor that was from a 97 turbo eclipse to find that they are different. But $1585? That is wayyy too high man.

[1995silvergst]

Well it has been a long time since I have been on this forum, sorry to bring up a really old post but I wanted to post the resolution on this issue. After all of the Dealers part replacements and lack of diagnosing the issue, they were finally able to call Mitsu hq and have a tech tell them to run a copper bb through the hard lines against the firewall and see if the passage is clear. It was not, the scilica or desiccant bag inside the a/c dryer came apart shooting scilica throught the system ( before I owned the car) So as they replaced parts and checked pressures the clogged hardlines were indicating high pressure at anything above Idle rpm and shutting the compressor down. Now I have been told this could have been diagnosed by checking the temps of the hard lines at various locations to narrow down where the blockage is, however I have no faith the dealership I took this car too has the knowledge required to work on these cars. Again sorry to bring up an old thread but I felt that this education should be shared especially since it cost me over 3000.00 do not go to mitsu dealers for a/c work ever.

[mebetter]

Cool deal nice update.

[kasumax]

Will need my a/c system fixed one day. Very helpful thread. Would like to hear what else you do have done, or will need done to your a/c system. All helpful info and thoughts are welcome.

[1995silvergst]

One most important thing is do not let a shop/dealer replace a part with out telling you why they are. What test have they done to show the part is bad, how did they diagnose it. Most shops/dealers have one to two ASE true technitions working and six to seven employees that do not have a clue. The factory service manual can be found online for these cars that has every test for the A/C system to diagnose a potential problem. My situation required a true technition that knows how to diagnose a problem with temps and pressures, the stealership I took it to was not that type of place. Pm me for specifics please I do not want post allot of info that people do not need. Here is a link to the manuals I spoke of in a previouse post by Steve a DSM wiseman thanks again Download a 2G Service Manual

[Tiki2777]

I may need some minor body work done, but thank God almighty for ice cold AC on a DSM.

BTW, dealers are such a hit and miss, it really does suck that they hire people that just really cannot work on cars.