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Discussion Starter #1
2002 Eclipse GS, 2.4L
Engine suddenly stalled and would not hold idle (without throttle) a few months back. Replaced the IAC, and the issue mostly resolved- but still had rough idle in gear; less so if the engine wasn't under any load in neutral. I had read here, that this wasn't unusual and that the ECU would eventually smooth it out (?).

Then the a/c compressor grenaded last week. Replaced the compressor, and now the engine will sometimes stall as soon as the compressor load is applied. It's inconsistent- sometimes the engine responds and revs up/makes the necessary adjustments, other times it stalls...

Suggestions for further troubleshooting? Thanks in advance for any suggestions.
 

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Better check your A/C charge.. An overcharged system WILL drag the engine down.. Along with that , you need to find out what your IAC count is. Might possibly need to re-adjust the SAS. Should see something right around 7 with no load.
 

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That's good point. Grab yourself a good set of manifold gauges and measure your high and low side pressures with the AC off. If the AC has been off for 10 or 15 minutes, the high and low pressures should be about equal. If they aren't, wait 10 or 15 minutes longer. If they don't equalize, you have a messed up throttling valve or a clog somewhere. If this is good move on to the next test.

If you can get the system to turn on, turn the fan up to full blast and measure the pressures and temperatures of the high and low sides after letting it run for 5 or so minutes. You want a low enough pressure in the low side for vapor at the evaporator outlet at the measured temperature. If it's higher, you're overcharged and probably sucking liquid refrigerant into your compressor, which will damage your new compressor. A laser thermometer or a thermo couple works great for this. If your system is working correctly, your high side should sort itself out. If you also want to check the high side, a good rule of thumb is the high side pressure should correspond with a condensed (liquid) pressure at the measured temperature at the outlet of your condenser but before the throttling valve. If your high side pressure is way above this, you're overcharged.

Look up some R134a vapor pressure tables to determine what your pressures need to be at certain temperatures to get vapor and liquid. A quick look at a table tells me you probably shouldn't be over about 300 psi on the high side. 250-300psi is probably fine. Depending on how warm it is outside where you are, I'd day no more than 40psi on the low side, but 35 psi is probably better. If it's cold out, it should be lower.
 

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Thanks, plot thickens a bit here.
I had done the compressor replacement at my son's off-campus apartment (his car at college)- made the two hour drive with every tool I could imagine needing, including manifold gauges and FORGOT the vacuum pump!

Took it to Midas where they of course charged an arm and a leg for evac-recharge.
When he hooked up the lines he told me there was refrigerant still in the system- which was odd because the lines had been off the compressor and wide open. Vacuum held for 20 minutes and called it good, then charged.
Now, I know nothing about the recovery machines- but apparently they can charge the system without the compressor running? I say this, because for some reason, the compressor was not kicking on when the ac was turned on. Tech ran a jumper from the battery to the compressor wiring harness and the clutch kicked in and it ran fine.They said, sorry, we don't know why the compressor wasn't kicking in and basically called their work good, and kicked us out.

Scratching our heads on the way back to his apt., pushed in on the fan speed switch to turn on the ac. Air started blowing cold (we're in FL, by the way...), but the green light that indicates "ac on" was not lit. When we got back I confirmed that indeed the clutch was operating now and blowing cold, despite the green light not being on.

To wrap up...

Anyone know, where the power for the green "on" light comes from- and whether this could somehow be related to the problem?

Can an evac/recharge machine charge a system without the compressor operating? Or were we getting jacked around? I can have him drive it back to Midas and have them re-check the pressures now that whatever gremlin was keeping the compressor from coming on in the shop seems to have resolved itself.
 

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The compressor doesn't need to run to charge the system. The fact that there was still R134 in the system is a sure sign of the desiccant (dryer) being moisture loaded or clogged. I have to ask, you said the compressor grenaded... What EXACTLY happened? If it was an internal compressor failure, you can bet that there was shrapnel sent all over the system. It is absolutely necessary to completely flush the system, replace the dryer and recharge with the PROPER oil and refrigerant amount. Just the fact that the dryer was open to atmosphere requires a dryer change. I see this all the time. We have customers that want to go the cheap route (replace the compressor and re-charge) and I can tell you this, almost every time, I have to go back and do it the proper way, which usually cost more in the long run.
 

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As for the light, the bulb may have just blown. Mine does the same thing. I have to listen for click of the compressor to make sure it's on or off.
 

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Discussion Starter #7
Compressor froze, clutch locked up- belt burned up and dropped.
At least that's what I surmise. My son said he suddenly lost power steering when driving. It was a cool day, he wasn't running the ac. I assumed it was the power steering pump and had it towed to a shop near him after speaking with them. I wasn't aware there were two serpentine belts and losing the one didn't affect the alternator and water pump.

I'm aware of the concerns regarding the compressor; it seems based on your explanations that the drier may be clogged. Because the system was charged without the compressor running and being able to check pressures we couldn't tell at the time.

I pulled the front end off the car a year ago to replace the condenser, IIRC the receiver/drier was integral to it (?).
Apparently it can be serviced (without needing to replace the entire condenser)because I'm finding these parts- but no info on replacement in the Tearstone manual.

 

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That's correct. Usually on one end or the other on the bottom of the condenser you will see a cap. Remove it and the dryer cartridge is in there.
Do yourself a favor though.... Buy a can of A/C flush, remove the lines from the condenser, compressor, and evaporator and flush EVERYTHING. Flush the evaporator and condenser after you remove the dryer. DO NOT FLUSH THE COMPRESSOR!!!! However, you should remove it and drain all the oil out, recording the amount of oil removed. Refill the compressor with the same amount of oil. The basic idea is to get all of the fine metal particles that are now everywhere in that system out. Be sure to replace the total oil to the exact amount, since this will make the difference in your charge. Too much oil = not enough refrigerant and vise versa. Also remove and replace the expansion valve since this can be affected by the shrapnel. Do all of this and that A/C will last the rest of the life of the car. Don't and you'll be messing with it again soon....
 

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Also, with an expansion valve system, your low side will be 25 -35 psi and the high side will be 125 -175 psi. This is assuming all is well... Orifice tube systems climb higher on the high side, mostly due to the fan cycling on and off. Pressure climbs to around 350 psi at which time the fan engages. Fan runs until the high pressure comes down around 150 psi.Our fans run constantly while the A/C is on which helps regulate the high side pressure more evenly. Compressor should stay engaged until the cabin temp starts to get cold enough to start freezing the evaporator. This is when the compressor will start to cycle.
 

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Yeah they pump refrigerant into the system and are supposed to measure how much they put in by weight. They can charge the high pressure side so they don't need to run the compressor to charge. Seems like they didn't verify the system was operating a proper pressures before they pushed it out the door?
 

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Yeah they pump refrigerant into the system and are supposed to measure how much they put in by weight. They can charge the high pressure side so they don't need to run the compressor to charge. Seems like they didn't verify the system was operating a proper pressures before they pushed it out the door?
Sure didn't...
It was late on a Saturday afternoon, and they apparently didn't feel inclined to check pressures- which seems to me they could have done when they ran the 12v jumper to the compressor and it kicked on. Which, is why whatever I can't do myself (like the long overdue timing belt) goes to a local shop I trust. Still don't know why the compressor wouldn't run without the jumper in their shop, but seems to have resolved on its own.

Also remove and replace the expansion valve since this can be affected by the shrapnel.
Hmmm... please tell me this is on the engine side of the firewall and separate from the evaporator- I sure don't feel like disassembling the dash to get to the evaporator, though I know it's just a matter of time anyway before that goes...
 

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Sure didn't...
It was late on a Saturday afternoon, and they apparently didn't feel inclined to check pressures- which seems to me they could have done when they ran the 12v jumper to the compressor and it kicked on. Which, is why whatever I can't do myself (like the long overdue timing belt) goes to a local shop I trust. Still don't know why the compressor wouldn't run without the jumper in their shop, but seems to have resolved on its own.
They probably had to do this to build the pressure enough to push past the blockage and trip the low pressure switch... SMH......
Hmmm... please tell me this is on the engine side of the firewall and separate from the evaporator- I sure don't feel like disassembling the dash to get to the evaporator, though I know it's just a matter of time anyway before that goes...
Unfortunately, it is bolted right to the evaporator. So yes, you have to take the dash apart to get to it, but you can't properly flush the evaporator without removing the expansion valve.
 

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Aaaahhh...that love/hate thing I have with old vehicles...
A lot of reading to do. Hopefully getting to it won't be like with my Expedition...
Probably be stupid not to replace the evaporator, along with the heater core,and whatever else needs it "while I'm in there"...

Thanks for all the helpful information.
 
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