Is there a HVAC filter in an 86? I don't want to tear the thing all apart right now to find out since it's 110 in the garage right now.

 

Nope, not in the C4. Now you won't get too hot in the garage.

 

The reason I ask is that I took out the fan speed contoller, and there is a screen that has staples in it on the right side of the cavity. That is to say, looking at it from the front of the car, the screen is on the left side of the cavity,......ie the right side of the car

 

Nothing in the service manual about it, but... i suspect it is a form of drift eliminator to keep
water from blowing off the coil and out of the grilles. Just a guess, but somewhat educated
one.

 

Well, my A/C fan seems weak. a couple years ago, it stopped blowing, and I replaced the fan.
A/C worked great.
Yesterday, coming home from work, I noticed it wasn't. i put a thermometer in the top vent, and it doesn't get any lower than 60 degrees.
60 degrees would be fine if the blower actually pushed a lot of air.
So, I made a jumper wire with clips, and turned on the ignition, but didnt start the car. I took note of the fan speed, then pulled the wire off the motor, and clipped the wire to the positive post of the battery then to the blower motor. It sounded the same. I put the car fan wire back on, and yup, didn't go any faster or slower.
so that was my question on the filter. I removed the fan control, and it is a solid state unit on a heat sink.
I need more fan!
so "10" on my fan speed indicator is full speed on the fan.
I put one of those "cheapie" gauges you get with a recharge kit on the low side, and it runs at about 55- 60 PSI, 110 degrees ambient, so, if my compressor was wearing out, what should the high side be if it was new?
The problem I have, is the gauges set I have have the old R12 fittings on them, and i have R134 in the system with 134 fittings. I will have to find some hoses or adaptors.

 

Is the 60# reading at idle? 60# is about 62* on 134a. That may be normal on a conversion
in your region (HOT), but it seems high to me. The high side pressure is key to diagnosing
it, but it looks like the compressor is not pumping well, or you are a bit overcharged.
I agree the blower on my '86 doesn't move as much air as i would like. We are in a heat
wave here ( cooler than your normal, i know) but mine isn't keeping up.

 

60 Lbs is at idle. (700 RPM)
Well, it was fine about a week ago. slow blower, but cooling at 45 degrees. The temperature has risen maybe 5-7 degrees since then.
I can reduce the pressure in the system. Not fun, but do-able.
on the road, not in the garage, we have rubberized asphalt. It raises the ambient temp on the freeway about 7 degrees.
It is not unusual to see 119 on the ambient temp gauge at 75 mph.

 

If its only 7* warmer outside since the change in supply air temperature
and you haven't added any refrigerant. It isn't likely overcharged, that
narrows it down to a hurt compressor. Don't trust my long distance
diagnosis, but it doesn't look too good.

 

There is a filter that isn't easily serviced. It's function is to only keep trash/dust etc from the evaporator core. In early cars there's no doubt it's usually clogged or nearly clogged. It normally would only be serviced in an evaporator core replacement situation.

You would need to remove the blower motor housing and it would be on that side of the evaporator core.

It sounds as if you're describing it's location pretty well!

 

Just to update, I wrapped the receiver/dryer in insulating material, and I got annother 10 degrees lower.
It was at 50 or 48 instead of 60. So I am going to wrap the bottom of it as well and lag the lines.
It will be interesting to see what I can get.

 

the evaporator core has a mesh screen on it and over the years it get plugged with mud etc. when I did the a/c on my 90 you could only see through a 1/3 of the evaporator core.

 

Normally, insulating the suction line drier is considered not worth the
trouble. But, the climate extreme you're in, it can't hurt & it seems to
be gaining a bit for you.

 

It is wrapped in insulating material on my Tahoe from the factory, so what the heck. I didn't drive it today, I made an appointment with the muffler shop to cut out my cats and install 2 bullet cats in their place. The left cat brick apparently has come apart, and is rattling pretty badly in the left cat housing, and in the left muffler.
I have true duals with dual cats and 91 vert mufflers, no precats.

 

usually has stuff on both sides of the evaporator. Usually a thin layer of foam material on the fan's side and a stainless steel screen on the other. These screens/filters are used as a diffuser to allow the air to pass evenly across the entire evap....same concept applies to the MAF sensor screens. These areas can get block by debris.



coil cleaner in use:


Home made air intake filter - keeps the debris from getting to the fan/evaporator in the first place:


I think your super high ambient temps are most of your problem. Great idea to wrap as much as you can to keep the heat out. I've tried to do the same thing within reason. I've got some insulation/wrap on the exposed aluminum portions of the dryer hoses that can be seen in the photo below.

 

MY QUESTION.............
Why didn't they put the evap core inside the passenger compt, and put the heater core in the engine compt?
or would that make way too much sense?

On the back side of the state Route 51, my outside air temp readout was reading 120. That is for about 2 miles. At the top of the grade, it clicked down to 113. My coolant temp was at 211 going up that grade. on the back side, where it sort of levels out, it was 197.

Not to start a row, I have an aftermarket radiator, and 160 thermostat. I also have true duals with dual cats, and a 383.
In the mornings, it is about 98 degrees, and the coolant temp is usually 187. Unless it's winter. Then it's usually 180
This morning, it was 101 degrees going to work, and it was 190 practically the whole way.

That being said, THis morning, I have lagged coolant lines and an insulated receiver dryer, and it was about 48 degrees coming out of the vent. On the way home, it was just below 60 degrees. Still not stellar, but kept me from sweating too much.

Engle, i didn't know it was a requirement to remove the engine when working on the air conditioner

 

Engineering hind sight is 20/20

It is amazing your tires don't melt on that 2 mile stretch of road. I've got some family that lives in Chandler, AZ that I visit from time to time so I've seen what happends to the asphalt out there in the afternoon on a mid summer day.

I'm guessing your fan(s) only come on @/over 180 F if your running a 160 stat and your getting those winter operating temps?

The C68 control head digital display only goes down to 60 degrees so it is within parameters I guess. 60 degrees on a 100+ degree day feels pretty nice.

It does make it a bit easier though.

If you haven't already you may want to check for debris between the radiator and condensor - if there is a buch of crap in there it will mess with both the AC and the engine coolant's ability of being as efficient.

2 years of crap build up between the radiator and condensor:


Myself I do run an undersized crank pulley that slows the flow of coolant at idle but I also run Dexcool coolant, h20, 3 bottles of Water Wetter, hard wired main fan (which is wired to spin all the time while the ingition key is in the "run" position) and a oversized radiator in my setup to keep things super cool here in the Florida heat.

My oversized radiator compared to the stock piece:


Newly installed radiator:

 

we probably have the same radiator. even at 120, the coolant is at 211 degrees, so I think all is well with the debris accumulation. why is your tank exposed on the right side?
sometimes this car gives a flawless performance.
Today was one of those days. The key, I think, is "keep moving".
FOR AN OLD CAR, IT IS A PERFORMER.

I wired my aux fan to come on when the main fan runs. and I'm using a 1994 Lt-1 alternator for 35 extra amps and a higher charge rate at idle.

 

Normally the upper shroud on the right side usually has long elongated slots that allow the trans (if auto) & ac lines can remain connected when the upper shroud is removed - over the years my upper shroud has been trimmed back in a few select areas a few times with the additions of larger radiators and/or trans coolers. The upper area of my shroud is the most exposed area but it still really doesn't effect any fan's "draw" functions in my application. I've got some relocated/rerouted smog/coolant hoses going on in that same picture so things may look a little funky aswell.