I beleive that I finally figured that it is "probably" the evaporator tube/orifice that is probably the culprit here. Just stopped getting cold air through and if I remember right since it has been since last summer when it went out, I might have noticed it slowly get there over a small amout of time... Was told it was probably low on 134 and added some but it only got a bit cooler but not even enough to make ANY difference. Bought some new gauges and hoeses and hookem up. I had good pressure on the low side but the high side never really moved and was low. I forgot to add that the clutch was cycling every 2 secs. at least. I ended up just unplugging the clutch to stop the cycling. So going by the book and what I saw under the hood, Tube off the evaporator on the firewall, the bottom one, was not cold to the touch really. So I think the orifice is plugged up.
At any rate, I planned on changing out the evaporator tube and hoping for the best here. Is there anything else that anyone can sugest to check before spending 150-175 bones on a new orifice?? Been in the high 80's and low 90's here the last 3 or 4 days and want to make sure this is fixed before the real heat shows back up...
Thanks for any input as usual...

 

What were the pressures? If the orifice was plugged you would have very high high side pressures. So let me know what pressures you have.

 

Korey, Thanks for the reply. ...
The gauges read like the following...

Engages >> Low side @ 52 switches ON the clutch, at 14 it switches Disengages >>OFF
Disengage>> High side is 70 and 102
The clutch was still switching within seconds also...
Blows only real warm .... not even a little cool. Although I didn't leave it on longer than about 2 mins.
It would be real good if you have something else that I might consider and check before dong the orifice tube. Which reminds me to ask if you have (or anyone that sees this) has replace this style tube (2000 4.3) as I would like to know if it is possible to switch it out with only removing the front fitting and be able to move it out of the way enough to R&R the tube. Don't really want to have to drain the DEX, lower hose, etc... Anybody have input on this please?

Thanks Korey, will be looking for and feedback.

 

Seems to me like it is still low on R134a. The low side should not go that low with 80* temps. The high side should also be higher than that. So I think some more refer is in order. Low side should be around 28-34 psi, and high side should be around 180-210 psi. TGhose pressures tell me that the freon is low.

 

I had added one of those tall cans plus one of the "normal" shortie cans. I think the shoert one are 8 or 12 ozs. Or are thet a full lb? At any rate, is there no way to determine how much is in the system orther than starting with an empty system and knowing exactly how much has been added from the git-go?
I bought this back in Oct I think it was and the clutch was cycling like that all the time but I didn't have a problem with it getting cold. Matter of fact, it got DAMN cold... I never really noticed the too frequent cyccling until later on but it was still working great... I can add more 134( how much, 1 can only?), but what would be a limit on that probably. Plus if that doesn't make it fly then, what would be your next thoughts?

 

16 oz = 1 lb

 

Is an orifice tube really that expensive? I thought it was just a cheap little plastic part (?). Or are you talking about replacing the evap?

 

I was wondering about that too. I bought one for my 89 and it was around $3. Have they changed that much?

 

No, they're not, even from a dealer they only cost $9.00. Anyway like kordog said, you are still low on refrigerant. This system holds 1lb.14oz IIRC, and it sounds like you put about 1 lb. in. The orifice is easily changed by removing the accumulator,if you have skill you can get it out without taking anything off. But the fact that you are asking these questions tells me that you should just remove the accumulator to get at the evaporator inlet fitting, IF you even need a new orifice tube. I'd charge it up a bit more (about another lb.) and add some leak tracer dye so you can fix it right after it leaks down again.

 

Well, the quote I got must have been for the whole unit then as I called NAPA and that was the price I was given and had asked for (orifice tube, not the entire evaporator unit). At any rate, I added the additional can of 134 an kordog had it right... don't reamember the pressures now, but it got cold... I used a manifold that has a sight glass in it. Think there is just enough in it now as when I got the can empty and let it run a bit more, the glass emptied.

Still, it was to ever need replacing, anyone know if the front tube nut at the tube would be anought to loosend and remove to allow enough room to R&R?

Thanks...