Who KNOWS A/C???

[nlzmo400r]

Ok, heres the delima. When I purchased my 240, it didnt have A/C (seized compressor). I am going to florida this wednesday morning, and want A/C for the trip. I went to NAPA,replaced the compressor and dryer, and converted to r-134a. I pull a vacuum only to find I have a whole in the high pressure line......had to go to Nissan, and paid $80 for a new high pressure line. Got that line in, pulled another vacuum to find a leak in the low pressure line...junkyard trip and $20 later, got a new low pressure line.... Vacuum looks good (25 under) so I add charge oil, then charge it with freon. The compressor kicks on and off like it doesnt have enough freon. The low pressure line got cold, but the vents never blew cold air. I return to napa and the guy tells me its probably my Orpherus tube (dont know how to spell it,basically fancy name for expansion valve). i replace that, pull vacuum again (agian 25 under) and charge it only to find that the compressor wont stay on. It kicks on and off as if it doesnt have enough freon. I bleed some out slowly with the car running and a/c on...finally the compressor stays on, however NO COLD AIR, and the low pressure line isnt getting cold anymore either, whats the problem??????????????????????- Thanks in advance, - DESPERATE FOR A/C

[prior...]

its hard to diagnose an a/c problem such as yours without hooking up pressure guages. you might not have even had a problem with the orphus tube.... what kind of fan setup are you running and how much refrigerant did you put in the system?

[monkeyspeed]

Make sure you to shake the can as you fill the system. Also, I filled up my prelude this weekend, but i had to get the meter to read about 70 psi before any cold air would blow out. I thought this was odd, so i tested the meter on my 03 Land Rover and it had the same psi: 70. I also tested it on my 00 Sentra and got 70 psi. Just to be sure my cars aren't blowing up on me, I tested the neighbors 04 Titan and got 70.

[meme]

if the compressor cycles frequiently; it could be the txv(blocked) or undercharge. what are the pressures; LOW , HIGH without the car running? what is the ambient temp?

[prior...]

txv=orphus tube. they are both different systems, and in the 240sx's case, an orphus tube is used. im gonna go with undercharge being your problem. i never liked those stupid cans you buy at autozone, b/c a ton of people just toss a can in if their car is blowing hot, reguardless. they end up overcharging, or creating other problems. get a set of guages hooked up, that will tell you everything you need to know.

[krustindumm]

The ORIFICE tube is not a part of the drier i dont believe. I wish i had my FSM on me, but in some cars it is in the low pressure line after the drier. just unhook the lines pull and replace.

[prior...]

i knew i was spelling it wrong... haha

[prior...]

the orifice tube is located between the condenser and the evaporator. it is integral to the line. system operaton goes like this.... compressor compresses the refigerant, it goes through the condenser... changing from a high pressure gas, to a high pressure liquid. it then goes through the orifice tube where it changes from a high pressure liquid to a low pressure liquid/mist before it hits the evaporator. then back to the compressor. im kinda rusty reguarding a/c... and im not sure of the specifics in the 240sx system. i left out the reciever drier/liquid tank/whatever....

[killjoy]

If the compressor kicks off and on it is either undercharged or overheated.