LS1LT1 Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
1,473 Posts
Discussion Starter · #1 · (Edited)
O.k so I recently replaced my A/C Compressor and TXV (the drier was the wrong part), along with new seals and a new pressure sensor. I took it to a shop to have it evacuated and serviced. $250 later they ended up removing some of the lines to figure out why it didn't turn on (there was no relay because I removed it to prevent it from inadvertently coming on). Long story short, new parts, unwanted $250 of labor (inspection, vacuum, and charge plus r134a).

My A/C doesn't blow cold at all! I was so frustrated that I bought a manifold gauge set, more r134a, and did a little research. Apparently A/C is an art. So, this is my problem. I pulled vacuum again (after a little EPA violating discharge) for 30 mins, let it stand for 40 mins; no leaks. Then I re-serviced it back up with 32oz. of r134a. Still hot air.

The pump will only come on for less than a second at a time. So I jumped the relay to keep it engaged at max fan max A/C I still get hot air.

This is the weird part my low gauge reads 15hg of vacuum at 1500 rpm and my high gauge wont go past 140hg ; it's 65 degrees out. Still hot air from the vents. Please help! I am going to order a new receiver drier today, but what else could be the problem? There is no leaks, any where. So I know I can rule that out. Should I put my old TXV back in when I swap out my drier?

If I am to understand this correctly I should see between 35-45 on the low side and 160-195 on the high right?

Please help, I live in Tucson and summer is right around the corner. It's only 65 degrees out now, but with black t-tops and black leather I need A/C now.

Thanks guys!

P.S. Before I replaced everything the A/C worked great until all the refrigerant leaked out (which only took about a minute from the input shaft seal leak).
 

·
Global Moderator
Joined
·
13,567 Posts
Have you thought about the possibility the compressor you bought is bad right out of the box?

Kind of confused about your vacuum readings, when compressor is running you should be getting a positive psi reading on the guages.

If you happen to have an obd 1 scanner capable of rear time sensor data, hook it up and see what r-134 pressure the pcm is seeing when compressor is off and when running.

And check for a/c codes, they are soft codes that don't turn on the check engine lights.

Finally, are you radiator fans turning on when you turn on a/c. I'm not 100% sure, but I believe pcm won't kick compressor on unless fans start when a/c switched on. Also if fans are not running you won't get cool air with compressor jumped.
 

·
Registered
Joined
·
1,473 Posts
Discussion Starter · #3 ·
No scanner. OBD I car with OBD II plug.

Fans are on. I thought of the compressor too. I'm just hoping that's not it. I'm gonna try and replace the drier best week and see what that does.
 

·
Registered
Joined
·
562 Posts
It sounds like there's a blockage somewhere in the system or a malfunctioning expansion valve. It may also be a compressor failure. It also sounds like it wasn't charged properly if you have a vacuum in the low side during any condition. There should always be positive pressure on both sides of the system during all conditions even engine off.

I would flush and re-flush the system (with proper A/C flush of course), dry it out with compressed air, and re-install the old TXV. When pulling vacuum make sure you pull a good 29"Hg vacuum, much less won't cause the moisture in the system to evaporate. And make sure you completely charge the system; I weigh the cans of refrigerant during charging and account for about an ounce of R134a left in each charging hose.

If that doesn't work, it's most likely the compressor, and if the system wasn't properly flushed (some manufacturers will require condenser replacement too), don't expect them to honor their warranty. A compressor failure spews tiny metal particles throughout the system which can kill a new compressor quickly if it isn't completely removed with proper flushing.

And there's no need to vent to atmosphere, just about any shop will evacuate your system for free (you're actually paying them in R134a).


Sent from AutoGuide.com App
 

·
Registered
Joined
·
1,473 Posts
Discussion Starter · #5 ·
I didn't flush the system. I am going too reinstall the old txv and replace the drier. I'll have a shop evacuate the system this time too. I'm flushing everything this time too. Thanks for the input guys. I'll keep you all updated.

Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
1,473 Posts
Discussion Starter · #6 ·
Alright, I flushed the system, replaced the drier, and reinstalled the old tvx. Then vacuum and charged the system. All is good. Ice cold AC!. Thanks guys.

Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
562 Posts
Glad we could help!
 
1 - 7 of 7 Posts
Top