97 UZJ80 AC problem? (1 Viewer)

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FJ40Jim

The Cruiser Whisperer
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Sep 26, 2003
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Location
Lancaster, Ohio, USA
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Tim has a 1997 40th that has been swapped with an engine & trans from a 2003? Tundra. 100K on the engine, 250K on the body & chassis. It runs & drives good and most of the swap is well done by the PO. Some details that have been straightened out are air filter, MAF, fan shroud, PS & ATF hose routing, cruise control...

The one thing that we are still struggling with is Air Conditioning. It would only blow warm air & Tim said he was really missing the AC on a recent road trip to the beach. It has the stock V8 compressor and a couple of custom fabbed hoses to connect to the FZJ80 vehicle plumbing. Initial check on the low pressure port showed it didn't have much charge.

As a first step, the receiver/dryer and the expansion valve were both replaced with new Denso parts. Seemed prudent, considering the miles on the body. Leaves & dirt removed from evap box. System recharged with 750gr of R134 and some oil. Optimum fill is allegedly 800-900, but due to there only being a low pressure port, it's hard to judge how much juice is actually needed. Heater valve was adjusted to get full close.

With all that basic stuff done, it only shows 5-10 degree of temp drop out the center vents. But (and this is a big but), it is piddling a steady stream of cold water out the evap drain, which makes me think the evap core is actually getting cold. I'm wondering if there is a problem with the blend door motor not working right, maybe not working at all, stuck in the winter position? At this mileage it would not be surprising if the automatic climate control crap was wonky.

I tried searching the forum, but couldn't find much about this sort of problem. LMK if I missed a good thread on climate control diagnosis. Thanks!
 
Who is Tim? Is this someone speaking in third person? lol

I checked with Ryan and Ryan thinks that it could be the HVAC controls. Have you checked the heater control valve to make sure the heater core isn't getting hot water to it? If you hit the A/C button on the HVAC controls do you hear the compressor cycling on?
 
Tim is a friend& customer. Normally I would avoid working on a swapped vehicle, but I _may_ have pointed out this truck to him when it was FS on 'mud a few years ago, so this may be my fault.:doh:

Yes, the heater valve swings from open to fully closed when the temp slider is moved from hot to cold.

The AC compressor does engage and runs continuously, no frequent cycling like a low charge situation. There is not enough charge in it to get either of the sightglasses totally clear, but sightglass is not the most reliable indicator of charge quantity, especially on r134 systems.
 
Running electric or mechanical fan? I did a swap and to to non oem shrouding and what not it didn’t pull air accoss the condos or enough to get the system fully charged and it would get hot and not take any more buddy and shop owner took a quick look and said you will not have enough air flow. I added a 14” user fan to the front as many do for slow going help with the ac. I could then get it to take a charge but it’s still not like the oem set up. But works well enough to stay comfortable
 
The mechanical fan on the V8 definitely was coming on when running for an hour in the shop. Scangauge showed ECT right at thermostat temp all the time, 191°-194°. Vent temp did drop another 5° when driving at 55mph. The best that it would do was 68° on an 85° day, on the road, 1800rpm, recirc on.

That's nowhere near the 40° of temp drop to avoid a warranty claim with Toyota. :lol:
 
Hopefully the 80 blend door actuator is easier to get at than a 03 Tahoe passenger side actuator. The Chev actuators have press on plastic gears that crack and just spin. :poop:
 
The AC compressor does engage and runs continuously, no frequent cycling like a low charge situation. There is not enough charge in it to get either of the sightglasses totally clear, but sightglass is not the most reliable indicator of charge quantity, especially on r134 systems.

Very frequent cycling results from overcharge. Correct charge will produce some cycling, as long as it's not too hot. Undercharged will produce no cycling.

Also, I don't see any reason not to go for a clear sight glass, unless your low side pressure is already above spec.

I think you just haven't put enough refrigerant in it yet.
 
I have another can of ~100gr freon & oil. That should get it to the official full capacity for an FZJ80. We'll shoot that into the truck next time its here.

I think it oughta work better than it does w/ 90% charge.

Googling for blend door problems turns up some forum posts for other 1990s Toyota's having same symptoms due to inop blend door. It is a more common problem on hi- mile cars because the blend door is constantly swinging back & forth trying to hit the target temp. It eventually wears out.
 

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