psmoss

I've searched here and elsewhere, but I want to post and get some ideas before I start going to replace the compressor.

The car: 96 Civic EX coupe, all stock

The problem: AC was not getting very cold, so I went to get it charged

I believe it was charged to about 48 psi.

After charging, it still doesn't get very cold, but seems to alternate between cool and more like ambient temperature.

However, I have a bigger problem than that. When the car is at idle with the AC on, the car will bog down to 100 rpms or so and start shaking, then jump up to 500-700 or so.

With the AC off, the car idles fine - around 750 rpm, and no CELs.

We noticed the AC is kinda noisy when it kicks on, so I'm wondering if it's binding up and that's what's causing the massive engine bog.

What sort of diagnostics can I do to isolate this problem a little better?

Thanks.

Adankid

yeah i somewhat have the same problem.

bump,
somebody help us out.

hOnda_hiEn

when it was charged..? was the system evacuated/recovered first..?? or did they just charge it..?? if not done properly.. it will not be at its prime temps..

as for the bog.. try cleaning out your iacv.. or adjusting for more air..

Former User

48 PSI on the low side? If so, it's overcharged with refrigerant. The low side should be 22-36 PSI. What's the pressure on the high side?

psmoss

Just charged.

hOnda_hiEn

yea thats not going to be good.. you got to recover the system before you charge to make sure you get out all of the charge out.. if you leave it in.. it will be overcharged when recharged..

wicked_gk

bump. i have the same problem and there still is no solution on this thread

fluctuating idle after i fixed my a/c. new compressor, vacuumed and recharged. idle goes crazy

wicked_gk

bump for help...

Nichelson_Performance

Yeah you have recover first then charge....I've always went by weight when I do a/c systems at work

Also your idle surge is more than likely from a voltage drop problem....a/c compressor+blower motor will draw lots of power which takes it away from everything else....one check would be get your alternator tested....imo the alternators most hondas use whether its a mitsubishi or denso alternator are underrated on amperage to run an ecu controlled car with all accesories running

Duane_in_Japan

Yes, and clean the entire throttlebody, when you have an AC request to the computer, the computer will tell the IACV to open a little further to increase RPM. Without AC and in Park, check idle speed, drop the gear into Drive, does the idle drop a little then come back up. Again in Park, turn the power steering and watch idle speed, turn all the way to the far lock and put a little extra pressure into the wheel, do you notice a bit of an increased idle.

If both of these test show an increase in idle then the IAC is working but it may be dirty, I should say the computer is telling the IAC to work, now you know that there is communication between the two and the circuit is good, once everything is cleaned and there is not better idle with AC request, then you start looking at an IAC that wont open enough, a compressor that is dragging down the engine due to overcharge or being worn out or a bad computer not controlling idle with AC request, which Honda is known for.

Mulkxican

I'm having pretty much the same trouble...but is anyone also having bogging troubles or sudden bursts of power while driving as well?? i thought it was my compressor clutch in my ac. so i replaced the ac compressor emptied and recharged the system. But it still boggs at an idol AND while driving but now it also Whistles/howls at me while driving (higher the RPM's the louder it gets)

Any Ideas?

97civicdx

You took the car in to a shop and had them recharge the ac system? They should have evacuated it completely and drawn a vacuum before putting refrigerant in. The civic only takes like 1 lb.

Mulkxican

well my buddy did it (a mechanic yes) but didn't have the vacuum and said we would do it right, later and make the ac even colder, but would that be the cause of my engine still bogging or the whistling/whining?

Duane_in_Japan

You have to find out what is making the noise, a vacuum leak or something else, the compressor, the compressor clutch or what. Did you try my tests above or do any cleaning.

Jimster480

48PSI on the low side is WAYYY to high. Whoever filled it that high is a idiot. The Idle bogs because there is too much freon (I know its not really called freon anymore) in the system. The and the reason it kicks on and off is because the pressure switch detects system pressure and flips the AC on and off accordingly so that it doesn't blow up. Too much freon will make it hit the shutoff level way too fast and the AC wont get cold. As far as the RPMs dropping to like 100 when the AC kicks on and then going back up; well that could be a dirty IACV or just a slow reacting IACV. Because the computer tells the IACV to open up more when you kick the AC on to maintain a better idle. I have the same issue because I dont have a IACV at all, but its not a big deal as my AC works fine.

Former User

You are responding to a problem posted more than a year ago, so the problem may already be fixed.

Jimster480

wait wtf. how did it appear in recent threads... :/

Duane_in_Japan

Well, that is what happens when other people hijack threads, no big deal, the guy seems to have the same problem as the OP so................

wck

I know this is an old thread; but thanks to this I was able to reverse what I did to my 1996 Civic EX... Here's my 2-cents...

Don't trust the gauge on those filler tubes. I bought the one from Walmart that is 18oz in weight along with a simple tube and a gauge on it... This one works great (better than the one with trigger type... those always leaked on me)... It definitely pushes the refrigerant into the system without leakage! (But again the gauge is a bit wonky).

The day I fill it was in the high 60's (F) ambient temperature range.. I used about 1/2 a can and the gauge remained in the green/blue zone (~25psi)...the whole time... When I started it, it was down at 15psi.. so I kept going and thought man.. 1/2 can already this can't be right..... so I figure I'd stop...

Then I didn't drive the car for a few days until today... (70F ambient temperature at 9am) and I experienced the drop in RPM whenever the compressor kicked in... and it did it repeatedly so I had to turn off the a/c to get to work... During lunch time it got up to 90F and I got home and put the gauge on....

The new reading (with engine running & ac on) was a whopping 65psi! I don't understand how the 2 readings are so different (granted outside temperature is warmer by 20F but still....) but why during the charge it never went higher than 25psi...? Can a difference of 20F ambient temperature mess with the pressure gauge "that" much? 25psi vs. 65psi?

Anyways...upon releasing the pressure and having it hover around 30psi fixed the constant on/off cycle of the compressor... (very noticeable as the engine hesitates quite a bit and you see the rpm drop even at 2500-2700rpm it would drop .. and slight hesitation on the freeway)...

So moral of story.. charge slowly.. and if in doubt.. wait a while and check pressure.. on a different day with different ambient temperatures...

I'm still scratching my head on this one..