El Camino Central Forum banner

1 - 20 of 32 Posts

·
Registered
Joined
·
391 Posts
Discussion Starter #1
Does anyone have any tips on how to increase air flow on the 86 and similar models? I have put a new blower in but still does not seem to put out as much air as I would like in the hot months. A/C is cool to cold but with not that much air volume, it still takes a while to cool down. You would think that with a cab that small, it would freeze you out!. Also read that the Choo Choo's had a heavy duty A/C?? anyway, I figure a better blower motor is out there somewhere?????]]\\\


thanks
 

·
Deputy Director, Region 1
Joined
·
2,566 Posts
Heavy Duty A/C? Thought choo choos were a rubber nose some ground effects, and decals.
 

·
Premium Member
Joined
·
3,167 Posts
I have a 86 Choo Choo, a real documented car, and the air will run you out. Its been 101 here today and very nice in the car. The blend door may not be closing and you may be getting hot air from the heater. To be sure thats not happening you could remove the two heater hoses and connect them together so you will eliminate the heater. WP
 

·
Deputy Director, Region 1
Joined
·
2,566 Posts
Was just reading E-Man's post on the Choo Choo's. I see where the confusion about "heavy duty A/C" comes from. In his thread he list the options. One of which is "V08 Heavy Duty Cooling". This refers to engine cooling not A/C. Possibly they had a thicker radiator, or a severe duty fan clutch, maybe a seperate trans and oil cooler like a tow package might have but doesn't refer to A/C.
 

·
Registered
Joined
·
388 Posts
The blend door may not be closing and you may be getting hot air from the heater. To be sure thats not happening you could remove the two heater hoses and connect them together so you will eliminate the heater.
Doesn't an 86 have a water valve that shuts off the flow of water into the heater core when the controls are in AC position. My 83 does. Maybe some one removed it (fairly common) or it's malfunctioning. My 83 will also freeze you out. I generally run it on the 2nd lowest speed.
 

·
Registered
Joined
·
388 Posts
Here's the location of the aforementioned water valve:
 

·
Premium Member
Joined
·
275 Posts
If you have poor airflow overall (the system switches properly but just doesn't "blow" well), it's very likely that the evaporator is blocked externally with debris, dust, dirt, and anything else sucked into the system over the last 26 years.
All of the air entering the MVAC system goes through the evaporator, AC on/working or not. All of that air is unfiltered. The tightly spaced fins of the evaporator make a dandy air filter.
As these cars age, this is getting to be a big issue. The only fix is to open the evaporator case and clean it out. Ideally, you would replace the evaporator. I've seen many 78+ evaporators that you just can't clean the crud out of totally. YMMV.
 

·
Registered
Joined
·
391 Posts
Discussion Starter #9
read the CHoo Choo article posted on this site
 

·
Registered
Joined
·
391 Posts
Discussion Starter #10
debris may be the culprit. I'm not talking about the temperature of the air though, just the volume of the air, so the debris make sense. I was confused on the VO8 cooling part. Nice info to know.
Forgot to mention, after sitting for some time, it takes the "blend" doors a long time to open. Sometimes it pops open suddenly with a loud pop like it has been stuck and been trying to open and all of a sudden unsticks.
 

·
Registered
Joined
·
391 Posts
Discussion Starter #11
I guess the rubber seals around the door can be replaced? or what??
 

·
Registered
Joined
·
388 Posts
Forgot to mention, after sitting for some time, it takes the "blend" doors a long time to open. Sometimes it pops open suddenly with a loud pop like it has been stuck and been trying to open and all of a sudden unsticks.
It might be overcoming a small vacuum leak. Mine did that until I replaced a couple of the hoses.
 

·
Supporting Member
Joined
·
4,477 Posts
Just for info, the blend door is operated by cable via the hot/cold slider on the HVAC control panel. You may be talking about the door that directs air to the dash vents and away from the floor/defroster. That door is controlled via vacuum, and as said their may be a vacuum leak.

For further info, hot water will pass through the Heater Core all the time, Except when the AC is in MAX Cool, and the temp control is full cold. These positions cause vacuum to flow through the Grey tube back to the water control valve under the hood and shut off water flow. These positions also cause the RECIRC door to open behind the glove box.

A lack of vacuum could cause the water valve to flow hot water, and prevent the Recirc Door from opening, and the dash vent door from opening. All of these could contribute to hotter air.
 

·
Registered
Joined
·
388 Posts
For further info, hot water will pass through the Heater Core all the time, Except when the AC is in MAX Cool, and the temp control is full cold.
Actually, that's not true. Control of the water valve is on the temperature slide. I'm not trying to argue. Go check it on your vehicle. I've actually tested this on three different Elkys; they can't all be wrong.
 

·
Deputy Director, Region 1
Joined
·
2,566 Posts
Actually, that's not true. Control of the water valve is on the temperature slide. I'm not trying to argue. Go check it on your vehicle. I've actually tested this on three different Elkys; they can't all be wrong.
Isn't that the same thing? Darbysan says the controls need to be on full cold. That means the temperature lever that slides left to right, hot to cold.
 

·
Registered
Joined
·
388 Posts
Not really. The top slide has no effect on whether or not the valve is open; only the bottom one and not on full cold; somewhere inbetween.
 

·
Vendor
Joined
·
4,363 Posts
For further info, hot water will pass through the Heater Core all the time, Except when the AC is in MAX Cool, and the temp control is full cold. These positions cause vacuum to flow through the Grey tube back to the water control valve under the hood and shut off water flow. These positions also cause the RECIRC door to open behind the glove box.
Control of the water valve is on the temperature slide. I'm not trying to argue. Go check it on your vehicle. I've actually tested this on three different Elkys; they can't all be wrong.
While both of these are true, this discussion warrants clairification:

When the mode switch lever is in the "Max" position, the vacuum switch on the temperature lever is bypassed and vacuum is supplied directly to the heater control valve to shut flow of coolant through the heater core regardless of temperature lever position.

When the mode switch lever is in any position other than "Max", vacuum to the heater control valve is controlled via the temperature lever vacuum switch and only in the full cold position.
 

·
Supporting Member
Joined
·
4,477 Posts
I've been giving this advice for years, so if I'm wrong I apologize to all those that I thought I was helping. My manuals are still packed from the move, so I can't argue my point one way or another with specific details. I think we may all be right to some degree. it depends on how HP11 did his test.

The water valve is vacuum controlled. It is either open or closed- nothing in between. Vacuum is only applied to the valve when NO hot water should be flowing to the heater core ( Max AC). From my understanding, and it is from memory ( I'm getting too old!) it was when the AC is on MAX and Temp is full Cold. You need heated air when in Normal AC mode to obtain a mix of temps, but in MAX you want no hot air mix. However, once vacuum is removed ( by moving one of the levers) water flow resumes. It all depends on which lever controls the small vacuum valve on the back of the HVAC control unit.

You may not feel it in the cab unless you move the temp lever far enough to open the Blend Door ( which is the cable's only function), which would allow air to pass over the Heater Core, get heated, and flow into the cab. This may be why you felt it was functioning only when moved to a middle position or more.

Some GM vehicles ( like the Roadmaster I got my Electronic HVAC Controls from) do not use the Vacuum Water Valve at all. They have Hot Water flowing all the time. Since I live in Vegas, I wanted the water controlled, so I made sure I got a vacuum source from the control that I could use to close the water valve ( and also open the Recirc Door).
 

·
Supporting Member
Joined
·
4,477 Posts
FYI, I was typing and thinking while Robert was posting, so I didn't see his post until after I hit return. Wasn't trying to do anything more than help.
 
1 - 20 of 32 Posts
Top