93 ZJ
New Expansion Valve (line), New accumulator, New compressor, New Evap, New clutch cycling switch. Pressures are rock steady, NO needle movement unless the clutch cycles (which is not alot) . 95 degrees plus ambient temp. 240 high and 44 low. Started out over charged and we pulled freon out to achieve those numbers. Was over 70 and over 275.

Blows very cool, with plenty of air flow but never gets cold. Heater core is 100% bypassed for the time being, NO coolant flow what so ever.

Why the devil is it not COLD?

Thanks
Ron

 

I honestly think it's a crap design in the early ZJ. What is your air duct temp at the center duct with the fan on medium? The best I ever got out of my 95 ZJ was 42 degrees.

 

No where near 42 degrees. I did not have a thermometer handy at the time, but best guess is somewhere around 60 degrees. Cool, for a 95 degree day, but darn sure not cold.

What Im baffled about is the pressure split, it could not be closer to perfect, yet I got squat.

Someone suggested I pull the system back down and only put back in the 28 oz it calls for. With that said, the pressures are right!

Thanks
Ron

 

I'm going through the same thing with mine. I just replaced the evaporator and liquid line, pulled a vacuum for a long time and charged the system. Good pressures, but not real cold.

 

Which refridgerant are you using? I know systems that were designed to run on R12 don't cool as well with R134. My older Chevys would freeze your chest hair, but my 89 truck converted to R134 was disappointing.

 

134a

Just for argument, we pulled it back down and charged the 28 oz it call for.

Pressures suuucked, but its ice cold. After 30 mins at highway speed its below 40 degrees. At idle in the shop we were over 60 psi on the low and about 280 on the high side. Neither of these numbers are what I would call ideal but its cooling fine, and based on at least one source the numbers are in the "normal" "range"

Ron

 

I miss R12, it worked so much better than R134a. It won't be long before 134 is phased out and we have to retrofit for the new stuff.

 

Of course the best stuff is ammonia, but only large industrial freezers can use that.

Just thought I'd throw that out there and see if it comes back. LOL!

 

Propane works great too.

 

Mom had a Chevy Blazer, the little one, the first year 134 was introduced. The condenser on that truck was thicker than the radiator. Lived on the NC/SC state line, where the temp hovered in the 90's with 85% to 90% humidity. That truck would put frost on your pumpkins in less than 20 mins! POURED condensate like a faucet.

134 is LESS efficient, however if you offset the efficiency with a little better hardware it works damn nice!

Ron