kenstoy

im having a problem with my a/c its a 99 taco with a 3.4 it blows air but not real cold air and the compressor is coming on every 30 sec or so then kicks out ,its not real noisey either it sounds normal when it is on.the air tries to get cold but its like something is shutting it down .any suggestions would be appreciated thanks, ken

gdutch

Have you tried putting more freon in it? If it's full then I'd suggest the A/C compressor clutch could be no good.

kenstoy

thanks,im gonna try that tuesday after work i will reply and let you know how i make out thanks again,ken

Ironmike4x4

First off I'd see about getting some manifold gauges and see what the pressures are on the high and low sides. If the pressures are normal (low side 25-40psi high side from 125-220 psi) then you'll be looking further. When I get an A/C complaint I always like to look at the pressures for a better idea of what's going on.

BTW: just a minor pet peeve of mine but "freon" is actually a registered trade name by DuPont referring to R12. Refrigerant is the proper term for R134-A Yes I'm a smart A know-it-all

kenstoy

i just tried to put some R134a in and it wouldnt take it the can i tried it with has a gauge on it and the pressure was going up in the danger zone and then dropped real fast ,as the compressor kicked in and off the pressure went up and down ,im not sure what to try next, thanks ken

Ironmike4x4

What was the pressure when the compressor kicked on? If it stayed above the danger zone then there are a few factors such as contamination or air in the system; restriction in the low side; too much refrigerant; over oiled system; or compressor failure but I'd need to know what the high side is reading too to further pinpoint the problem.

DailyDrive

Why not just take it to a shop? Tell them to take a look if it's low, and if so, fill it up. properly.

There are usually no diagnostics costs for these types of services, and you can always turn around and leave if you don't like something.

Ironmike4x4

I would double check on that. My shop advertises "free A/C checks" but that's just simply for me to stick a thermometer in it and NOT to do a static pressure check or running pressure check. Diagnostic time is usually .5 labor/hour depending on the shop and how much more complicated the problem is.

Every shop I've worked for and other friends at other shops do the same thing so I would recommend you check.

kenstoy

thanks,ironmike i will get back to you on the exact psi, im getting gauges this weekend.i will repost what i find.i try not to go to shops unless i have to im pretty handy with alot of repairs i just dont have the extra money,thanks again ironmike ,ken

elblako91

I have a similar problem mine comes on real cold and then fades out and it feels like the AC isn't on. THen it comes out super cold again but then blows out fog/smoke. hmmmm << I hope I didn't overcharge it. Subscribed to this thread as i may find some useful info.

Ironmike4x4

Overcharging will cause the pressures to be too high and usually you'll hear the compressor buzzing and often times it won't be cold. The fog/smoke issue does this occur on the passenger vents? I ran into the same issue w/ my wife's Eclipse last week. Came to find out when I tinkered with her A/C last year I undercharged it just barely to make it colder but keep the compressor running. Doing this caused her evaporator to freeze up and would cause a "fog" to come from her passenger vents.

People tend to think more refrigerant equals cooler A/C. False, actually less is more, it's quite a bit complicated to explain and requires vacuuming the system literally overnight. I've gotten mine down to 38F at the vent. The basic idea is to add just little enough that the compressor kicks on and off more frequently but not too frequent from too little refrigerant, also pulling a vacuum for a longer period of time helps to get the moisture out (I'm quoting my HVAC instructor as I'm still not sure how he gets this idea, but he told me these methods to help get my A/C temps down so I won't argue).

EDIT: elblako I just thought of another scenario from when I was just beginning with the "smoke" deal. Master tech of mine explained that in some cases the humid air doesn't form into a liquid fast enough to drain out the vent tube. If it's on outside air then switch it over to recirculate and see if it helps.

dallison

I would recommend taking it to a qualified reputable shop that can do this for you. If it is low or high on refrigerant(sic) it will give you problems. Too low will not allow the compressor to kick on and too high you may get the same thing.

FogRunner

Pulling a good deep vacuum does get the moisture of a system. The way it does this is by dropping the pressure of water it reduces the boiling temp just as putting water under pressure raises the boiling point. When you put the moisture under 29.995 inches of vacuum it boils at room temp and is pulled out by the vacuum pump.

Moisture itself will not cause the system performance issues unless there is ALLOT of it in the system where it can ice up on the metering device and restrict it. The main issue with moisture is long term because it mixes with the oil and heat from the compressor and forms a acid that eats up the bearings and seals in the compressor.

There are several ways to charge or recharge a A/C system so more technical than others. The easiest way to recharge a automotive a/c with little technical knowledge is to discharge the system and recharge by the weight specified on the sticker under the hood.

Also since the 4runner has a expansion valve instead of a orifice tube you can charge with the sight glass on the dryer. The way to do this is turn on the A/C on recirc and max fan and start slowly charging into the low side while watching the sight glass on the dryer and charging till it turns clear.


FOG

kenstoy

hey all,found the problem lol just my luck the can of r134a i purchased from the store was not working right the end that connects to the low side wasnt releasing the r134a go figure i took it back and they exchanged it and the new one went right in and now i have cold air. so i guess the psi readings that i first had were wrong because now the psi is staying in the filled range.thanks everyone for your help,ken