Diesel Furnace

stopping · Post by **stopping** » Mon Feb 26, 2007 2:30 am

hello everyone....

Does anyone here know these things at all? I am interested in rebuilding it but it smoked when in the van(there were no holes in the body or conbustion chamber......just lots of smoke in the cab from the furnace..... I just cleaned it and there
was some gunk on it so I cleaned the air sides very well and we shall see.

Also I would like to know how to calibrate the pumps to the blower if anyone has suggestions. And how to wire it whilst removing the H-volts coil and what is that black/ with yellow wire coming off the combustion blower?
I need to know what it connects to.

I want to be warm!

libbybapa · Post by **libbybapa** » Mon Feb 26, 2007 9:22 am

I don't have any info on the furnace other than pointing you to the diesel-vanagon yahoo group and thesamba.com to post both places.

On another note, I looked at your blog and noticed the bit about the hassle you had with the WBX tranny front mount. I think you can just unbolt the four bolts that mount the mount to the chassis and flip it around.

Andrew

itzdshtz · Post by **itzdshtz** » Mon Feb 26, 2007 10:36 pm

Hi Steve, there is an electrical wiring diagram on page 97.50 and 97.51 of the Bentley Repair Manual for the diesel version of this heater.
There is also a trouble shooting guide and info on all versions of this heater starting on page 82.1
The black and yellow wire comes from a set of points that is inside the blower, as the blower runs, these ignition points are opened and closed by a cam lobe and they trigger the coil to spark and the fuel pump to pump.
This B/W wire goes to conn. 1 on the coil.
I have worked on these at times, usually it will take quite a bit of time to fix.
I hope you have a Bentley Manual, if not I could copy some pages for you. Let me know.

Herman

VanagonMark · Post by **VanagonMark** » Mon Feb 26, 2007 10:48 pm

I got a factory unit in one of my Diesel Vanagons, and I don't think I have turned it on in 16 years! BTW it was a $400 factory option on the 1982 sticker

Almost forgot that little burner was under there!

stopping · Post by **stopping** » Sun Mar 11, 2007 2:53 pm

Herman thank you very much... I will look at that today I hope. For me I don't need the coil as a changed the spark/glow plug to the required glow plug for the furnace. The re-wiring to jump around the coil is ambiguous to me and have no idea where to find it in the Bentley (yes I have one... it suggest the coil be cut out but doesn't say how to hook up the C-blower to the pumps.) Thank you again I will take another look at the wiring diagrams.

I have been through the trouble shooter but not much point till I figure out where to connect this yellow wire with a black line. ....Yes it ran to the coil so I guess I will connect it to the coil again but if anyone knows of a better way or has seen reference in the manual let me know. It worked before so it will work again.

I would love to get this furnace working not just for the remaining winter (6C and sunny today) but for camping in the spring.

Andrew.... You might be right about that tranny bracket... I think I flipped it every which way but I was a mechanical upstart back then..... but there again ...not much has changed.

itzdshtz · Post by **itzdshtz** » Mon Mar 12, 2007 12:19 am

Hi Steve, I didn't know that you had the later type glow plug, you can take your high voltage coil out and insulate the terminals of the Violet wire and the Yellow/ Black wire.
There should be a wire in the electrical plug of your combustion air blower that goes to both your fuel pumps.( the points for your fuel pumps are in your combustion air blower as well, they are separate from your ignition coil points)
Check with an Ohm meter if you have a bad connection between the pumps and this plug.
To check your fuel pumps, take the wires off and put 12v on one terminal and neg. on the other. They click only one time, until you take the wire off and on again. Make sure that your fuel filter is clean and the small hoses from the fuel pumps are new, they usually crack. The output of these pumps is very small, so a tiny leak causes the heater to malfunction.

stopping · Post by **stopping** » Mon Mar 12, 2007 3:18 am

Now I get it.... thanks H-man ....datsdshtz ....guess I asked in the right place.

I will keep you posted.

stopping · Post by **stopping** » Tue Mar 20, 2007 7:17 pm

Hello folks...

The good news is that my furnace works! The bad news is that it still smokes.... a diesel van hot boxed with diesel fuel.... lots of it non stop this time! It will run continuously and produce think billowing clouds of diesel smoke (seems totally unburnt like it's dropping into the hot air side of the furnace and getting very hot)... white smoke.

Exciting though toxic the heat produces lots of heat and clean exhaust, just little wafts of black smoke at the exhaust.

Any idea whats going on here? Too much fuel?.... not atomizing right?

Steve

itzdshtz · Post by **itzdshtz** » Tue Mar 20, 2007 11:11 pm

Hi Steve, it looks to me that you are getting way too much fuel. Try to run it with one fuel pump disconnected and see what happens, then reconnect the pump and disconnect the other pump and run it again. Can you see a difference? I wonder if the small output pump has been connected to the big output pump wire and vice versa. Green/Red should be connected to the big out put pump and Green/Yellow to the small out put pump. By running on only one pump you should be able to determine which pump is putting out more heat and this would be the big output pump that is suppose to be connected to the Green/Red wire.
Also check that the Green/Yellow wire connects to terminal 87a on your fuel pump relay.
Green/Red should go to terminal 15a on the combustion air valve.
Did you pressure test the combustion chamber when you had the heater apart? I don't understand how you get combustion gasses inside the vehicle unless the chamber is cracked or your air circulation blower picks up combustion gasses. Is the heater exhaust elbow connected?
Is the piping to the air circulating blower in good shape and does it connect to the inside of the van?
Herman

stopping · Post by **stopping** » Wed Mar 21, 2007 5:11 pm

Thanks Herman... I will try the taking the pumps off one at a time.

I think it is fuel somehow leaking down around the combustion chamber or the chamber is literally flooding with fuel and leaking down to the inside air side of the furnace.

I did not pressure test the chamber itself... the top of the water was at combustion chamber so not much pressure. Anyhow... the weld of the fireside of the furnace looks new and clean. There is no rust or holes in the combustion chamber, except that part of the (asbestos?) insulation ring, surrounding the combustion chamber, is missing bits but it looks like normal wear.

The amount of smoke I am taking about could not be explained by a crack and could not be combustion gases..... way too much smoke!

What would happen if the leads to the fuel pumps were backwards? Would the pump run backwards and would it be more forceful than running forwards?

No elbow on the heater exhaust and there is great flow from the circ blower to the cab... all those connections are new.

Thanks Herman

Steve

itzdshtz · Post by **itzdshtz** » Wed Mar 21, 2007 10:43 pm

Hi Steve, I think that the fuel pump would still work the same if you switched the wires.
I hope that switching the pumps will help.

Herman

stopping · Post by **stopping** » Wed Mar 21, 2007 11:30 pm

Just to be clear the smoke is not coming from the exhaust. The smoke from the exhaust is black and there is not very much of it. The smoke in the van is white and takes a few minutes to start smoking. After five - seven min. it really gets billowing (from the main air out in the floor of the cab).

Maybe I should wave a chicken over it!

Steve

libbybapa · Post by **libbybapa** » Wed Mar 21, 2007 11:34 pm

If I'm not mistaken, the two circuits (heated air and combustion/exhaust) are completely separate. Therefore, either you've got something burning off the heated air parts (cleaning solution?) or youve got something not sealing correctly.

Andrew

stopping · Post by **stopping** » Thu Mar 22, 2007 12:37 pm

That's right Andrew.... I'm thinking I have a fuel leak from the glow plug/ fuel atomizer thingy and it leaks down the outside of the combustion chamber (within the air heating side of the furnace.)

Also I might not have it wired right. Maybe the pump is on all the time..... constantly pushing 12v and way too much fuel

I was unable to figure out where to connect the infamous wire (yellow with black line) to the pumps. The pumps have separate wires and separate controls.... I was unable to figure out how to get the YB wire to communicate with whatever controls the pumps. So this could be the issue too! Now the YB wire is connected to the coil where it was connected (I think)... with the Black wire on the other side (of the coil).
Question.... What is the control wire that returns to the relays..... switching between high and low volume pumps?

Let me say for the record that the furnace seems to work perfectly. There is for example less heat when the temp switch is set lower and more heat when set higher. The exhaust from the heater is clean with the rare small puff of black smoke. It runs continuously, producing heat of many levels. So this is to say that, to my mind, the trouble is a fuel leak.

I will test the flow of the pumps, check for the suspected fuel leak and look for another way to connect the wire.

I will be doing this today so maybe I will have news later.

Steve

stopping · Post by **stopping** » Thu Mar 22, 2007 5:19 pm

Question.... was answered by your previous (first message) so the yellow/bk wire is to be insulated and not used as is the violet (appearing black under my light) good.

The pumps might be reversed as you said... will correct if need be today.

The fuel output from the hose at the glow plug is one small drop per click and totaling little more than a tablespoon for the run on time. (about 120sec I think)

I will check the pump wiring and get back to ya.

Steve