ATownZ28

I've recently replace the a/c compressor, and when I run the a/c for about 30 minutes and over, air slowly stops coming out the vents. I can hear the fan (running on max blast) but little to no air is coming out. When this happens, I pop the hood and notice ice collecting on the accumulator.
I'm afraid to run the a/c and damage my new compressor. Any ideas what this could be?

2001NBMZ28

Sounds like the charge. The air slowly not coming out of the vents with the fan on is the evaporator icing over too. Is the compressor staying on? Too low or too high the sensor should shut it down.

YoMommasTA

iTrader: (1)

you need to add more freon,your charge is too low causing low pressure=evap freezeing up.Add a few more ozs

ATownZ28

The compressor was so recently replaced, is it possible I have a leak somewhere?

2001NBMZ28

Could be, or maybe wasn't charged right: From my helms:

55-50 * ambient, 32-27 PSI low side/157-187 high side
66-75 * ambient, 36-41 PSI low side/177-218 high side (starting here humidity becomes a factor too, these are for above 40%)

YoMommasTA

iTrader: (1)

Noiw that i think a little more about this.the other problem could be that the sensor is not reading properly and is not shutting the compressor off when the pressure is low.i think the cutout is at about 22psi.Put some gauges on it and take a quick look.Below 22psi the compressor should be off.If it is turning off but still freezing up then add a few more ozs.If its never turning off replace the sensor.If it doesn't shut off below 22 its gonna freeze up.the compressor not turning off could explain why it burned up

Marc 85Z28

iTrader: (8)

You need to have your pressures checked, especially the high side. A small restriction somewhere could cause the high side to be abnormally high, but within spec and causing an even larger pressure drop than designed. Did you inspect the orifice tube for debris?

If everything checks out OK, you may need to install an evaporator temp switch. Basically its a small thermometer that attaches to the evaporator (or tubes leading to it) that will shut the compressor off if it reaches freezing. Most newer cars have these as AC systems are becoming more and more effecient.

BTW - Who rebuilt the compressor?

JR HAWK 9

iTrader: (3)

we have a V7 compressor which is a variable stroke compressor. There is no shut off switch....the compressor just destrokes it self when needed. I found out a lot of info on this site and here is one of my posts trying to fix the same problem you are having.

http://www.autoacforum.com/messagevi...AR_MSGDBTABLE=

01WS6/tamu

iTrader: (37)

The pcm uses a evaporator temperature sensor to determine turning the clutch on and off. Since it is freezing up you need to check the evap temperature with a tech2 or other scanner that will let you look at that data. All the three wire sensor is, is a loss of charge switch and high pressure monitor for the pcm. The pcm looks at the pressures from this switch on the liquid line in front of the expansion valve to determine compresor on off operation due to high pressure or low charge, cycle fans on high or low. As old as our cars are starting to get I have come across a bunch of them with the evaporator face plugged with dirt hair lint and any other little piece of crap the blower can pass on to it. If it is beginning to get plugged it will also freeze up due to decreased airflow over the surface.