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turbo ac issues

I keep going back to the boost switch cutting out the compressor.

Random idea... you could wire up a small LED light on the dash in series with the compressor clutch power wire. That would act as an indicator and let you know if the clutch is still engaged or not while driving.
 
Random idea... you could wire up a small LED light on the dash in series with the compressor clutch power wire. That would act as an indicator and let you know if the clutch is still engaged or not while driving.

Yeah a meter, test lamp, LED, etc into the compressor circuit would tell you if the compressor is being turned off. I thought of mentioning this too.
 
Back from the dead ...
So I read the other AC fix that is pretty good. It seems we are on a similar path (I will be upgrading to a bigger E fan next)
So I went back and drained the system, checked that the valve, checked it had 7 turns out, also took it apart to clean it.
I blew out the evaporator and there was some oil that collected in the "u" at the outlet. Just for kicks, I also opened up the bottom line at the condenser, but nothing really came out.
Was able to blow off the evaporator through the recycle air flap, it had some leaf matter but not that bad.

Installed stock receiver/dryer which said it was good for 134a.
Vacuumed for 30 min, let it set for 30 more, good to go.
Added 36 oz of new 134a. Not cold at all.
Added 5 oz more ( maybe condenser held more) not cold.
around 55/225 at 85 and 2K rpm. Give up for the nite.
New plan is to install a new valve.
In the morning check ambient temp/ pressure. Seems good according to chart.
So maybe I should drain and replace Evap valve. Take out 22 oz or so and things start to get coldish.

Take it for a spin, still gets hotter like before. Like heater hot.
Reconsidered heater valve which I already replaced. Checked the in/out heater hoses in the cab, all good.
Checked lines in engine compartment. Reversed!

So it looks like the hot water was reverse flowing. The valve I put in is directional. It probably held until the water pump spun up, built enough pressure to overcome valve.

Have removed some more freon and was able to get 28 /160 psi at 83 ambient, 2k rpm.
Infrared gun says low 30's , temp probe says 50's. Not sure which to believe, feels pretty cold. The exit line at the evaporator has condensation.
Most importantly it's good at freeway speed. I think the heater was the main issue. Now I just need to tune the AC

Not really sure how much freon I have in it. Today I was offered the use of a new recovery machine . I may evacuate so I can actually determine how much freon is in it.
It feels like there is only about 24 oz in it. (started 3.5 cans in, 1.5 cans sitting on the bench).
Thanks for all the help.

I think I will make a fabric heat shield with snaps to cover the high pressure line as it enters the cab. I think the exhaust / turbo heat must add some temp.
Also cram in a bigger aux electric fan. Trying to figure out a way to cycle it off when the car is moving. It originally came on with sensor in the rad. I added a a relay to kick it on when the compressor is running. Maybe hook into the idle switch at the throttle?
 
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Have you checked vacuum/pressure in the blend door lines at highway speeds. Just because you have good vacuum at idle doesn't mean it won't leak out when cruising. A one way valve will let it go to 0 if there's a leak and you're cruising in boost or near 0 vacuum.
 
It was hard to do while driving. I did check when I was under there that I could cycle the door open and closed. Car off.
remove and check the white vacuum bubble tank under the heater for leaks. It turned out the rubber connectors / reducers were leaking. I ended up zip tieing them to seal them. Are they available?
I searched but the pics didn't look right.
 
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I use wood clamps to clamp off the heater hose lines to test for temp drop. My 93 got almost 10 degrees cooler when I replaced the heater valve with one of the dave setups. Couldnt tell it was leaking before I clamped it manually.
 
I use wood clamps to clamp off the heater hose lines to test for temp drop. My 93 got almost 10 degrees cooler when I replaced the heater valve with one of the dave setups. Couldnt tell it was leaking before I clamped it manually.

That?s good info right there. I always wondered if it would make a difference. My sons 93 is impossible to get cold when last year it was working well.
 
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