92 Honda Civic AC/Idle/Stall issue - stumped!!

[rbarwic1]

I just recently bought a 92 honda civic dx with 166k miles.

 

I am having trouble with it stalling when coming to a red light and putting it into neutral. This does not happen when the AC is off - it has no problems. With the AC on, and only when it is hot outside it sounds like the compressor (possibly something else, im not a mechanic) is short cycling. It turns on and the car starts shaking really bad for about 5 seconds, then turns off for about 3 seconds, and repeats over and over and over.

 

I have checked the main relay - everything checked out ok.

Replaced spark plugs, rotor and cap, fuel filter, air filter, timing belt, axles, and had the fuel injectors cleaned.

 

I have already put more money into the car than I paid for it, so I am stuck with her now.

 

Seems to only really start happening when it is over 75 degrees outside. I have checked the AC with a hose from autozone at about 70 degrees outside and the pressure was normal for the freon. I am not sure if it would spike when it gets hot outside and be overcharged?

 

I have read many forums and have gotten this far...but now I am stumped. Any ideas would be highly appreciated...I cant figure out where to look next.

 

Thanks in advance!!

[James Matteu]

Check your idle speed and connection to the ECU from the A/C ON input wire.

[rbarwic1]

James Matteu: I do not have a tachometer in my cluster. How can I check my idle speed other than just by ear (which I know is unreliable). Which wire is the A/C ON input? (see below)

 

I am looking http://honda-tech.com/showthread.php?t=2309184 at an ECU diagram for the 92 honda civic. Connector A appears to have an A/C Compressor Clutch (15 black/red wire) and Connector B has an A/C switch signal (5 blue/red wire). Which wire is the correct one?

[James Matteu]

You need to make sure both are connected to what they're supposed to be.

 

Figure out how to check the idle speed, there's many options:

Change your gauge cluster

Use a data logger

Etc

[rbarwic1]

You need to make sure both are connected to what they're supposed to be.

 

Figure out how to check the idle speed, there's many options:

Change your gauge cluster

Use a data logger

Etc

 

What about attaching a tachometer from autozone? How many rpms are normal for idle?

[James Matteu]

I have no experience with getting one of those tachs to work.

 

500 to 750, but check your Helms Service Manual.

[rbarwic1]

I figure that would be easier than changing the cluster - I will post my findings if I can get the tach to work

[Cuba Rodriguez]

If the problem only exists with A/c on it is highly likely that the compressor itself is failing.... first with car off, reach down to the compressor under the hood. there is a plate on with what looks like triangular pattern that sits on pulley....spin by hand....this should have SOME resistance by should spin somewhat with ease and definitlely should be able to turn by hand. That is the clutch for the compressor. If it has trouble spinning you can stop there and know the compressor is failing, otherwise the next step is to remove the belt that drives the compressor and now spin the belt driven pulley part, that should definitely be easy to spin with no resistance or very little. If not then again compressor is going. Keep in mind A/C is the most expensive work besides motor and transmission, and if it turns out that the compressor is bad, do yourself a favor and replace accumulator/drier, orifice tube or expansion valve, AND compressor and o-rings on any fitting opened.

 

The shaking felt for those few seconds should be only when the clutch is engaged.... with the car engine running you can also confirm this by turning on A/C then going under hood and visually inspect compressor and it's clutch. Shudder starts then that's when you should hear the "click" and see the clutch spin along with the pulley in unison. "click" off and shudder stops then you should see that clutch plate stop spinning and pulley still spinning with belt. Now typically when the "clicks" are very short in between, it;s a sign of low freon levels, BUT because you have that shuddering/shaking that's typical that the clutch is seizing and in turn making a much higher load on the engine.

 

Symptoms you describe COULD be something else too, but in my experiences this would be easiest to check and more likely the issue.

[rbarwic1]

Thanks Cuba - I will try twisting the compressor when my car cools off. Just realized the radiator is leaking, so I have to sidetrack and replace that real fast. I will reply later

[Cuba Rodriguez]

it's always something... ... lol

 

ok and can't wait to read update!

[rbarwic1]

So unfortunately I had to cut the hoses off as 22 year old hoses would not budge. I cant get my hand down there far enough to twist the compressor. The triangle piece you described I believe is facing the left tire and there is a ton of plastic protecting it from road hazard. I assume I will have to take the tire panel and possibly the bottom front plastic shield off to get to it. Is there an easier way to access it that you know of? I tried reaching down between the belts but there is no way. I dont even think my 6 month old daughters hands are small enough to get down in there!

 

I bought a tach, and found where I need to connect it to the engine - however now that the radiator is off I cannot start the car until I get new hoses. Will get hoses and post updates tomorrow after work.

[Cuba Rodriguez]

you are correct on the piece facing the tire....couldn't reach it when the radiator was out? How about jacking left side wheel and either take off wheel or try turning wheel far right even? but if I'm not mistaken there is a cover there too but held by only 2 10mm bolts... it stinks that you have to go through so much to hand check it.... well if you can see it well enough from the top safely, to try running engine just to confirm that the shuddering occurs as I described above with the clutch engaged

 

sorry - I just reread your last post. I must've misread and repeated some of what you said

 

of course tmrw AFTER hoses are in...lol

[rbarwic1]

Nope, the radiator was on the other side. I can reach the back side of the compressor through the void where the radiator was, but that doesnt do much. I will try looking at it tomorrow - by taking the panel off if its just a few bolts and see whats going on - im afraid if i uncover that panel something else will break! haha

 

So just to make sure I am tracking - twist the triangle piece and see if it moves freely, then take the belt off and twist the pulley and see if that moves freely? The triangle and pulley operate independent of one another?

[Cuba Rodriguez]

yes, you are correct, they work indepently from eachother. the triangle piece is the clutch (engaged electrically) and only spins when A/C is on and still only intermittently even then. That's what you will be looking for when car is running and doing the visual inspection with A/C on.

[rbarwic1]

Thanks for the clarification - I will post tomorrow with an update. Thanks!

[James Matteu]

I've delt with seized compressors. They don't bog a motor down into a stall. Rather, the compressor impeller shaft (the part the clutch is attached to) stops spinning and if clutch is engaged the pulley stops spinning as well. At that point, the belt screams as it is forced to continue moving and either slides over the A/C pulley or crank pulley. Any other accessories using the same belt tend to suffer simultaneously. Eventually the belt snaps. Even bearings starting to fail will cause belt slippage. Rarely does anyone just let the car stall out, they give it a little gas to keep it going. So in the unlikely event a failing compressor be able to stall the motor, a quick tap of the gas will squeal the belt before it stalls out.

 

Given my experiences with failing compressors and the lack of anything close to what I described above coming from the OP, I opined the issue lie with an idle either set too low or an ECU failing to compensate for additional load.

 

What concerns me further is that the OP is unsure of himself to the point of being afraid to remove a splash guard. Nothing wrong with checking the compressor, and you will have to remove the splash guard to check it. In fact, I encourage you to check the A/C compressor. You need the experience of working on your car so you can shake off that noobish glow you exude. Secondly, you should be familiar with what a good bearing feels like sin the event the compressor, or any system using bearings, should fail.

 

I'm not a fan of the tachometers they sell at auto part stores as I don't feel they add value to the vehicle as would a gauge cluster from a higher trim level. Additionally, solving a problem while adding both value and esthetic appeal is a win win win in my book. That being said, you have it now so get it working so you can see what your engine speed is. If I'm not mistaken there should be a diagnostic tach signal in the engine bay you can connect with rather than making a permanent-ish instalation in the car.

[rbarwic1]

James,

 

Thanks for the information - I dont plan on keeping the tach, just using it for diagnostic purposes. And for the record, I am not afraid at all to remove the splash guard, I just wanted to check and see if there was a different way before jacking up the car and pulling them off. No reason to start pulling things off unnecessarily. Thanks for the info - I will hook the tach up tonight and let you know exactly what the idle speed is. Thanks!!

[James Matteu]

Please look into the specs on idle speed and then run through the issue: cycle the A/C and see if your idle bumps up to compensate.

 

Check those connections to the ECU.

 

If the idle speed is too low then run through the usual suspects as to why it is too low.

[rbarwic1]

James,

 

I had the fuel injectors cleaned as the shop thought that was what was wrong with it - so they charged me 200 bucks to clean them and the fuel lines which is pretty vague so I am not sure what exactly they cleaned. I was going through some of the forums and I think I might clean out the FITV and the IACV while I have the radiator out anyway. The fuel injectors made a huge difference and now it only stalls about 10% of the time it used to, but it is much worse when it is hot outside. This week we will be in the mid 80s so I am sure I will get more experience with it as the last 2 weeks have been in the 50's and 60's.

 

Thanks again for your help, I will post my idle numbers after work.

[Cuba Rodriguez]

@James... I have had that happen at least in 2 different cars and both were different makes (the compressor issue) and the fact that the car was acting up with only A/C on made me think of those occasions but I could be wrong too.... which is why I suggested hand checking the compressor and clutch....

 

either way he has good suggestions to check for from the both of us..lol

[rbarwic1]

James, here is what I found out. With the car on and the A/C off the car sits at about 500-550 rpm. When I turn the A/C on it drops down to about 300rpm's and then goes up to about 400rpm's and stays there. (30 dollar tach from autozone reading)

 

Cuba, I didnt have enough time tonight to take off the splash guards to hand turn the compressor, but visually the car did shake when the clutch engaged. No shaking at all when it turned off. The clutch is the thing that is short cycling (i.e. clicking on and off every few seconds)

 

Thouhts?

[rbarwic1]

So according to http://ww2.justanswer.com/uploads/dinotapia/2011-07-26_194836_iacv_adjustment_civic_92-95.pdf my car should be at 810 +- 50. It appears that you need to raise the idle speed a certain way (not just twist the nuts on the throttle) Can you guys confirm?

[James Matteu]

True. He's got some work to do.

 

Unfortunately, there is a strong possibility the shop simply put a fuel additive into the tank and charged you for cleaning the injectors.

 

For my C27A4, it costs $50 per injector (50x6=300) plus shipping to send them out to be refurbished and flow tested; and tthat's with me removing them and reinstalling them myself. Have a shop do this for you and i could see them adding about 4hrs labor at $60 per hr and we're looking at almost $540. You would know this was done as they would have provided you with a flow analysis. So, likely they charged you for about 2hrs of head scratching and a bottle of sea foam or a similar product.

[rbarwic1]

James, so what should I do next? Focus on getting the idle speed up?

[James Matteu]

Yes. Get the idle speed on spec. Here's the caveat: simply adjusting the idle MAYmask sone or more underlying issues...

 

1. The compressor.

 

You don't need us to tell you it shouldn't be cycling on and off every few seconds. The ECU takes a moment to decide to bump up the idle, on my car about 3 sec. This is normal, Honda doesn't want to burn fuel unnecessarily if added engine load is temporary. So if the compressor continuously cycles on and off, the ECU never has a chance to "catch up". There's a pressure switch with two wires on the High Pressure Line, you can close the pressure switch with a paper clip (car off, then turn it on, then turn on the A/C) to temporarily force the compressor clutch ON for the purpose of diagnosis. Do not leave the compressor engaged like this for a prolonged period of time, otherwise you risk possibly damaging the compressor.

 

If the compressor still doesn't stay on when the pressure sswitch is bypassed, you may have a mechanical issue with the compressor itself. Unless you're experienced in rebuilding a compressor, then at that point it would be a good time to seek a second opinion (not the sea foam mech) and see about replacing the compressor if necessary.

 

If the compressor comes on and in general sounds fine, then you should seek an automotive HVAC service center that can check the refrigerant levels, pull vacuum to dry out, and recharge the correct amount of refrigerant.

 

If it is found the system is properly charged and the compressor functions mechanically but is still unable to function on its own, then you have an electrical problem that would require further diagnosis.

 

2. Idle speed.

 

Given the age of the vehicle, I would look into cleaning the Idle Air Control Valve and/or making sure it is working properly. This includes looking for vacuum leaks on ALL the vac lines.

 

If you haven't done so already, verify the A/C input lines at the ECU are connected properly.

 

 

3. If everything checks out okay, then double check everything starting with the vacuum lines.

 

 

4. If everything is still okay, then consider adjusting the idle speed at the throttle body.

 

 

Don't forget to come back here and let us know how it goes. Be objective and have fun!