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Discussion Starter · #1 ·
I joined these forums around this time last year seeking help with a tranny issue, after much helpful information and trouble shooting I was still forced to replace my transmission, but was very satisfied with the assistance and efforts of the Planet Isuzoo community!

I come today with a semi-minor yet uncomfortable problem......

1998 trooper 3.5 4x4 .......My A/C unit is not working correctly the blower blows fine I have charged the unit with a freon/oil blend/leak sealer blend, the clutch activates yet the air is not getting cold at all... And another symptom I have noticed is while I am driving and I attempt to activate the A/C it seems to bog down the engine and I feel a sense of rubbing or grinding of some sort during acceleration. So prior to taking it to a shop and potentially paying a large sum I decided to consult the wise Isuzu aficionados here on the forums for advice!
 

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i am no ac expert but it sounds like you system is over charged , i don't understand the rubbing or grinding , is that with the ac on , i would get a set of gauges and evac the system , then recharge it .

also because of the hot weather the ac system high presure will be much higher than it was when the weather is cooler, google up the ac presure vs temp.

the ac for sure should not bog down a 3.5 engine
 

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Discussion Starter · #3 ·
The gauge that comes with the charger reads at perfect charge yet it still blows warm to ambient air no cooler then outside temp....I may need to invest in a gauge set and evac system it would probaly cheaper the getting it serviced at a shop but funds are tight at the moment.
 

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Was your system just low before or was it completly empty? If the system is empty or has been opened you have to have a vacuum pulled to remove all the air before charging. Those gauges that come with the charge kits are usually crap. I had one that said every thing was fine but when I put my real gauges on, it was way over charged. You need to be able to see both high and low pressures.

Its also possible you have too much oil in the system. I only use the recharge cans that are only refrigerant no oil, stop leak, other crap in it.
 

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x2 for overcharge and getting a set of gauges if you want to know what's really going on.

When overcharged it will not blow cold and the compressor can definitely moan and groan when in that state. These systems can be finicky to charge (top off), really have to take into consideration the ambient temp when checking pressure (higher ambient = higher pressure). Shoot for at least 80-90 degrees ambient when doing the charge. Also at idle and above 1500 rpm pressures will vary significantly, so you have to find the right balance - to achieve "cold" at idle while not having pressure go too low at rpm to hit the cutout switch too soon.

Sufficient gauges can be had for $50 or less, and unless the system has been open to the air and lost all pressure, shouldn't need to pull a vac on the system.

Of course the only way to do it exactly right is to have the refrigerant recovered, pull a vac, and refill with the system's rated refrigerant amount...but where's the fun in that :lol:

Lot's of sites out there for info if you google, here's a helpful one: http://www.aircondition.com/tech/questions/82/

Good luck!
 

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I had the same problem.. I had to replace the txv on mine. I'm not sure what the other Isuzu vehicles use.. An orifice tube is a lot easier (and cheaper) to replace!

But yes, before you do anything.. Get a set of gauges and hook them up to the high and low end and turn the a/c on max. Make sure the gauges are CLOSED!! Lefty loosy, righty tighty... I would rent a quality set from autozone. $100, a little pricey.. But you get every dime of that back when you return it. Make sure to save your receipt!

Post the low/high pressure here.
 

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Discussion Starter · #7 ·
Many Thanks to everyone who has posted a reply! it seems the first step will be to rent or purchase a set of proper gages before I proceed any further. I will get some gauges test the high and low pressure and return with the feedback.
 

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Airconditioner is really important during summer time, even me, I cannot stay long on hot weather I did prepared already the things to be needed and fix everything. the car air conditioner, our solar air conditioner also the split system to survive this summer.
 
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