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All New A/C and still not cold. Vacuum Issue?

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dwithers

New Member
Joined
Jun 12, 2003
Messages
135
I've replaced all my A/C parts and it only blows 58 degrees out of the defrost. I know that is the default and I'm looking for the problem.

What are the colors of the vacuum lines and where do they go?

I've checked the flapper door that lets hot air in. It's closed and tight. The Cold/Hot slider switch works.

Any Thoughts?
 
Vacuum Canister

Should be located under the drivers fender well. Make sure that its operating properly.

What freon type are you running?

What are the psi of the discharge and suction?
 
I installed the parts and had a proffesional flush, vacuum and charge the system. I'm not sure what the readings were. He told me it everything was fine in regards to the guage readings.
R134A. He checked everything and could only come up with a vacuum leaks and or the vent door was open letting hot air in.
 
No I did not. I will when I get home. The canister in the front drivers side area right? Behind the headlight?
 
also, it's hard to get an accurate reading if the air is flowing through the defroster air vents. The evaporator requires alot of air flow for the gauges to read accurately. If not you can just fooling yourself. A low air flow through the evap will cause the guages to read lower on the suction side resulting in a false reading
 
Have you checked to see if you have vacuum to the control head?
 
I removed the controls fom the dash tonight. Everything looks fine. All the hoses are hooked up. I can't hear any hissing, however, I don't have a vacuum guage so I am unable to test that. I checked the metal cable that runs from the controls to the vent for the Cold/Hot. That works. I checked the flapper that lets in fresh air. That was closed. It has to be a vacuum leak but I can't find one anywhere. I traced all hoses. All seem okay. Even the canister looks okay.

Any other ideas?
 
This is from memory, so I may be a little off.
The vac source starts at the intake block, goes under the TB to the drivers side. There is a check valve "near" the FPR and driver side valve cover. I think it t's from there, one for EGR, other for A/C (and maybe more). Anyway, the vac line goes to the firewall on the drivers side where there is another check valve, then over to the passenger side to the airbox area. Long story short, I "think" there's one vac line entering the cabin. You don't need a vac gauge to see if there's vacuum, its pretty evident.
 
Are you checking outlet temps with the doors open or the windows down?

Also - you may have a rotten heater control valve - letting hot coolant into the heater core. Some of the newer replacements have plastic :eek: internal valves, and disintegrate over time.
 
So you are getting cold air but through the defrost and probably the lower heater vents. Mine did that last year. The door to distribute the air to the vents was stuck or blocked by something. It started working all by itself.

Scott
 
56 to 58 degrees with the windows up. Both the blender door and the other door are working properly.
 
Temp control

When you move the temp control all the way to cold you should hear a thump. That's telling you the door is closing all the way shut. If it's not making that noise the door may not be closing all the way, and maybe letting hot air in.
Also check to be sure the heater control valer in the engine compartment is working, most I've checked are not.
The easiest way to check the vacum system is to conect the line to a vacum sorce like a A/C vacum pump. This way it's quiet and you can hear better.
When the vent control is on MAX you should have most, if not all, of the air coming out of the dash vents. If you have a noticable amount of air coming out of the defrost or heater vent, the vent control door needs to be checked. There is only one small black plastic vac line from the engine that controls this. It goes in through the firewall on the passesgers side. With time they do crack and leak. One of the main places to look for a leak is the vent control head. It's made if plastic and they do break. Check to see that the white plastic button that holds the vac control is not loose. If it is thats your problem, your loosing vacum there.
To check the A/C you'll need to get the pressure readings. If the compressor is not cycling on and off, you maybe overcharged on 134.
With the engine running, when you move the vent control dose it move the air from the different vents????? Or dose it just stay in one place???
 
The temp control does work. I can hear the thump and I can view it opening and closing. The white button is okay. I've removed the whole unit. The blender door and the other door works properly. Both open and shut. I've replaced most of the lines under the hood. I have vacuum at the canister. I"m not sure what the problem is.
 
Does the air move???

Does the air move from vent to defrost to heater when you move the control????
 
58 at the vents

To check the A/C you need to get the pressure readings. I've seen alots of conversions that have been over filled with 134. This could be the reason for the warm air.
Was the temp taken at idle ???? Should be taken at 15 rpm. What was the outside temp??? Really need the pressure readings to tell if the A/C is working corectly.
I'll try and scan some information from my manual and send it to you.
 
The readings were right on the money. The heater valve isn't sticking, the doors aren't hung, etc. The controls work. There has to be a vacuum leak some where. I'm not sure why it doesn't blow cold.
 
Are you saying 58* isnt cold enough?

Scott
 
The tech. should have put in 80% R 134A of the original R-12 amount. If there was too much refrigerant oil put in the system, it will not cool as good also.
 
A/C Temp at outlet

Is the 58 the temp at the outlet??? Depending on the outside temp, it should be around 40 at 1500 rpm on high blower and MAX.
Try misting some water on the comdensor and see if the temp comes down. If it dose you have to find out if the fan is pulling enough air through the condensor to cool it off. The cooler you make the condensor, the cooler the A/C will be.
Do you have the evap shield still on???? I've seen some cars with it missing and not not cool to well. The turbo down pipe get really not, and it's right in that area.
You might try to stop the hot water from entering the heater core temporarily and see if it helps.
It still could be overcharged. Try going for 30 to 35 low at idle, 25 to 28 low at 1500rpm. If the high goes over 300 mist the condensor with water, if the high goes down you need better air flow through the condensor. Hope they flushed the condensor when they did the recharge.
 
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