North American Turbocoupe Organization



A/C question
firstsvo Offline
Senior Member
#1
88 TC. I had the a/c evacuated and recharged recently. Was already converted to 134 by PO who also put in a new dryer. Problem is the car only blows at about ~60*. Brought it back, the low side is 50, the high side is about 100. Alldata says the high side should be between 150-200. The a/c guy said it's probably the orifice tube. Does this sound correct? Also, from looking at rockauto, it looks like the orifice tube is in the line that runs from the condensor to the firewall, under the turbo, I think. Am I looking at the correct line? I am going to replace the whole line as it is only like $25.00. Rather not cut and all. Also, how important is it to vac the system as it is all new refrigerant in there now that I am going to lose? I am not an a/c guy, so any input is greatly appreciated. Thanks... chuck
White '88 auto mostly stock, Black '88 5 speed nowhere near stock
Reply

teal95 Offline
Senior Member
#2
That doesn't sound quite right. If the orifice tube was plugged the high side would be lots higher and the low side would be lower. I am not an expert though, it's entirely possible I'm full of sh**. I just had to recharge mine earlier this week 4 years after I converted it over. It took about 1/2 a can. After the recharge it was at about 200 on the high side and 30 on the low side.

steve
'83 & '84 GT turbo EEC-Tuner
'85.5 & '86 SVO twEECer
2x '87 & '88 TC QuarterHorse
'93 LX 5.0 notch Moates chips
3x '95 & '96 GT
Reply

Matt S Offline
Posting Freak
#3
I agree with teal95. If the orifice tube was plugged the high side would be alot higher. About 60* sounds right for 100lb high side. I charge mine to about 200lbs high and that ends up to around 30lbs low on a 65-70 degree day. On a HOT day the same charge would probably be around 250lbs which is the highest I'd go with the HR980. As careful as I was putting it all together it still leaks.

R134 is fairly cheap to where I don't mind filling it back up at the beginning of each summer. I drive my car very little though.
Sold it Sad*
Reply

Keith Nubel Offline
Posting Freak
#4
You don't have enough information posted to actually determine the real problem. It sounds like it could be low on charge or the strainer in the orifice tube could be plugged up. The orifice tube is crimped into the liquid line making it impossible to service. The 50lb suction pressure bothers me. This sounds high for a 100lb head pressure. It could be an indication of a weak compressor. The orifice tube should have been replaced when it was conversion to R134A.
1985 TC
Reply

firstsvo Offline
Senior Member
#5
For all I know, it may have been replaced. It actually looks "newer" and has a Ford tag on it. I brought the car to a place today and it wouldn't take any more as far as the computerized machine they used, said it was full. That was the guy that suggested the orifice tube. I don't know what condition the compressor is in, but it seems to work and there are no leaks. Tonight on the way home, it was about 70* and the car blew at about 40*. When it was like 95 the other day, it blew at between 75-80*. THAT sucked. I was going to replace the ENTIRE line with the orifice tube in it. They do have just the orifice tube, but you have to cut the hose and somehow or other put it all back together. The orifice by itself is like $4. Also, (again) the line with the orifice is the one I described above? Thanks for the replys guys, keep 'em comin... Chuck
White '88 auto mostly stock, Black '88 5 speed nowhere near stock
Reply

Protowrxs Offline
Member
#6
Quote:...The orifice tube should have been replaced when it was conversion to R134A.
Sorry to hijack a bit but I am going to convert my non-working AC shortly to 134 and didn't read this in the tech info. So the host from the condenser need to be replaced as well?

I had planned on replacing the dryer and have just put a used condenser on since the old one was crunched.

Guess I need to do more research.

Heh, it would be better just to keep my windows down than blow 80 degree air.. ;-)

-Stephen
http://www.StephenNolen.net
'88 TC/5spd/Gillis/Tripminder/stock being resurrected
'85 SVO Mustang
'69 Mustang 347/TKO in progress
Reply

firstsvo Offline
Senior Member
#7
Is it possible that the orifice is leaking or broken apart as opposed to being clogged? That would make sense to me as far as the high side being low and the low side being high. Kinda like a little too much "free flow".
White '88 auto mostly stock, Black '88 5 speed nowhere near stock
Reply

teal95 Offline
Senior Member
#8
I didn't change any hardware when I converted mine. The only hardware work I have done on any of them was I always replace all of the o-rings with the newer material that is R134a compatible (viton IIRC). For the first car I got a couple of packs of o-rings from the parts store. After that I went to a local supply house that did seals and got bulk quantities of the sizes I needed. For the first 3 I did as directed and completely removed the compressor to drain it. As I never got anything out of them I quit doing that. If you are adding liquid oil add it while you are replacing the o-rings. I would then vacuum the system down. I would usually leave the vac on the system for 4-6 hours before shutting it off. Leave it pump off and make sure it holds the vac level. The extended vac pumping and hold time makes sure you have the all of the water out of the drier. Yes, the vac will literally suck the water out of the drier. Once it will hold vacuum for 30 minutes you are ready to charge the system. Just make sure you have put enough oil in the system by either pouring liquid in or using the charge+oil cans to start with.

steve
'83 & '84 GT turbo EEC-Tuner
'85.5 & '86 SVO twEECer
2x '87 & '88 TC QuarterHorse
'93 LX 5.0 notch Moates chips
3x '95 & '96 GT
Reply

riisitas Offline
Member
#9
Stephen I thought about converting to R-134 but I stayed with R-12 and I'm happy I did. There was no real significant cost difference whether I refilled my system with R-12 or R-134. R-12 was a little more expensive than R-134 but not enough to prompt me to make the switch. All my system needed was a little maintenance with some new seals, a replacement hose and a compressor oil check/fill. My A/C is now ice cold and running great. Personally I think the only way to do a conversion right is to change out the R-12 equipment. Jim Whelan at Motion Dynamics has a conversion kit made for the SVO that will also bolt on to a TC. It's a complete professional design with a new R-134 compressor, condenser, dryer, hoses brackets and everything you'll need to make a proper conversion. From what I hear the output is ice cold.
1988 TC 5 Speed Stock
Reply

Protowrxs Offline
Member
#10
Thanks for the input riisitas. I have a few cans of R12 left. Guess you have to go to a shop anymore for an R12 fill though.

The car had the condenser crunched so the system has been open for some time. I have to replace the dryer so I thought I'd move to R134. The car is a beater for the most part but I'm working through the issues to get it back in shape. AC would make it a bit more enjoyable around here :-) Guess I need to think it through more.

Thanks again!
-Stephen
http://www.StephenNolen.net
'88 TC/5spd/Gillis/Tripminder/stock being resurrected
'85 SVO Mustang
'69 Mustang 347/TKO in progress
Reply





Users browsing this thread:
1 Guest(s)



Theme © iAndrew 2018 - Software MyBB