AirSpeed VW Community Forums
General Forums => Air Speed Lounge => Topic started by: purple turd on January 25, 2014, 12:31:01 PM
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has anyone bench tested a gas heater? are there only 2 wires to power and ground to make it operate? I have a clean looking heater that I may install if I can test run it first. 2 wires cut[probably from original car} and 2 fuel lines [probably from original car] ???
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There should be 3 wires, a red + and brown - as well as a smaller (usually) grey trigger wire for the relay. You'll want to make sure the diapragms in the fuel pump and pressure regulator aren't petrified or glued shut with bad gas and it's always time well spent opening it up to clean all the wire connection terminals on the resistor block and grounds as well as the easy to get at outside stuff, glow plug BN-2's need full voltage to light reliably. Start spraying PB blaster on the flame switch nut now because it'll be stuck pretty good.
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(https://airspeedparts.com/forums/proxy.php?request=http%3A%2F%2Ffarm6.staticflickr.com%2F5242%2F5378605137_7313ba8457_o.jpg&hash=4e7bcdb61bd7f83b08d620326fe3cd7a89302339)
I have. Assuming you have the correct switch, pump, wiring harness and Gas heater, then in the case of the BN2, there are just two wires to worry about: Power and Ground. The rest of the wires are all part of the gas heater wiring harness.
-Dave
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So far everything seems to operate properly.i figured out the wiring only 2 wires, the rest are one with the heater. The pump runs but wont prime. The fuel pump pumps air but wont draw fuel so the heater wont fire.replace oe pump with a cheap facet pump? Had it all apart the diaphram looks good, no crud, fuel filter is clear...just not gettin fuel
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............. The fuel pump pumps air but wont draw fuel ..............
A leak in the inlet line or filter will do that.
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So which heater do you have? Early BN2 with the Hardi pump, fuel pressure regulator and separate metal fuel filter or the late BN2 as in Dave's picture. If is the early one your fuel pressure regulator diaphragms may be rock hard and not allowing the fuel to pass through. If it is the late one you need the proper pump that delivers the fuel in pulses not continuously. Those pumps are becoming hard to find. Early pumps and regulators can be rebuilt if you can find the correct diaphraghm material.
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The heater has a filter. Wing nut and an aluminum housing with a bail wire. 12 volt, hardy pump, 4 screws holding the pump housing to a plate.contact points in electrical part.
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So no fuel pressure regulator on top? Gas line would go to it and then to the combustion chamber. If so (no pressure regulator) it would be a B2. There should be an ID plate on the side of the heater. Do you have a manual? If not find a reference on the Samba and print off a copy. Then systematically go through all the heater functions to eliminate such things as loose/corroded wiring as an issue. With respect to the pump priming I have had to prime a pump that hasn't run for a long time using a vacuum pump. The diaphragm has to be super flexible to function. I have a few here that have diaphragms that appear to be flexible but not enough so as to pull fuel through them. Oh and they run just fine!
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Send me your email and I'll hook you up with the Eberspacher technical manual. It's the Bentley for heaters.
-Dave
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That would be awesome. I just need to figure out if I can use a cheapy fuel pump or if I need to hunt down oe parts. Pretty sure the whole heater is original to my car so it would be really cool to use it. Jbmac@shaw.ca
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One line from tank to pump then out of pump to chamber with a what looks like a return line teed from chamber to tank. So in , out and chamber all in 1 block at chamber inlet
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That sounds much earlier than a 70 heater.
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Even all the holes in the body of the car where the heater is plumbed...exhaust, fan, etc look factory
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A quick pic or two of the heater and the pump would be nice. If you don't have a place to host the pics do it on the Samba. The fuel pick up and return line (all in one) is near the corner of the gas tank, right. And on the metal id plate on the heater it says B2 and 12 volt right?
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Got it fired....smokes like a bugger.now what
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When you first start them up, especially after failed starting attempts, they smoke like mad. When it's running correctly, and you're stopped at a light, people will probably roll down their windows to tell you your car is on fire.
I run mine a little lean so it doesn't smoke, but I don't get as good heat.
-Dave
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There must be a way to clean it out. I replaced the fuel pump with a 1to 3 psi pump.i dont know if that is too high or low. How do u run it lean? Im still in research mode. I did get the emailed book but my tablet wont open it
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You're probably running it way rich. The factory pumps, at least the BN2 pumps, pulse. They squirt a touch of fuel, pause, squirt, pause, squirt, pause, etc. On the later model pumps (the only one I have direct experience with) you can tune the amount of fuel that is released with each pulse. The manual I linked you to has testing procedures for setting the correct amount of fuel per hour. Based on the recommended settings, with me burning less per hour I'm running "lean".
What kind of pump are you using? If I can find a useable pump (that's less then $200) I have about 6 gas heaters ready to go for sale.
-Dave
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23042 performance world. Like $50 at mopac.it does pump in pulses but may be too much.
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Ahh, yeah, that type of pump isn't compatible with your gas heater. You're definitely flooding your heater, and using that type of pump with these is dangerous.
The following link might help explain it better: http://www.shoptalkforums.com/viewtopic.php?f=49&t=141560 (http://www.shoptalkforums.com/viewtopic.php?f=49&t=141560)
You might be able to get that style of pump to work with your older heater, my experience is limited to the later style heaters with metering pumps.
-Dave
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I thought the pump may be too much but when bench testing, the return fuel hose has no fuel coming out which led me to think flow was close. Im gonna play with the oe pump a bit more
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That pump should work with that system, odd about no return flow, perhaps a metering jet is plugged?
Here's some reading that may help:
http://www.thesamba.com/vw/archives/manuals/eberspacher_trouble_8542.php
http://www.thesamba.com/vw/archives/manuals/7_63_eberspacher.php
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Well I cleaned out all 3 metering jets (they were already clean) tried putting a restrictor in the fuel line...then it wouldnt fire just eventually flooded.removed the restrictor just went to 3/16 fuel hose and 1/4return. Everything works perfectly. Good heat output, glow plug operation, it fires in only a few seconds and stays lit as it should.the dash light and switch operate perfectly. But.....it produces so much stinky smoke it would not be feasable to use. It has about 20 minutes of run time and the smoke doesnt seem to be lessening. O snap
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Im running out of options.the heater box heat works well but was just trying for better yet.i wish I knew if a factory fuel pump would fix the smoke.. I hate to give up on a heater that burns and blows heat so well but smokes like a sawmill
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The next step I'd take is adding a restriction to the line from the pump, either a small Weber jet shoved into the hose or better yet an adjustable needle valve of some sort like a fishtank air valve but fuel proof. you can choke down the output of those clicker type pumps without overheating them, apparently 24GPH@2-4PSI is way more than the heater needs, most only burn around a pint an hour at best.
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1 Litre per hour is the BN2 fuel rating.
~16ml per min
-Dave
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purple turd, do you have the B2 heater with the Hardi pump or the early BN2 heater with the Hardi pump and the fuel pressure regulator? Couldn't quite figure that out from the posts. I have been working off and on with an early BN2 that came from a 71. I don't know quite when the switch was made. I've also worked on the B2's but that was a few years back. Mostly late BN2's and BN4's these days.
As well, did you check the points gap on the pump as per the manuals that BUSDADDY referenced.
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It has a hardi pump with no separate regulator. Sorry I would have posted a pic but im not computer smart enough to do so. I put a smaller orofice in the pump to heater line with an air regulator.. seems much better. Installed it in the car today but gonna really keep an eye on it for a bit.would still rather have an oe pump
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The heater seem to be working. I havent tried to start it outside in the cold yet but it runs fine inside.theres what looks to be a fresh air intake right beside the exhaust that I havent run outside yet so its drawing under the hood.im a little worried if theres a backfire I wont have a car anymore.there is a j shaped tube that looks like its supposed to extend the intake into the wheel well. Intake right beside exhaust?? Seems wrong to me
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The exhaust should have a deflector that diverts the fumes back and keeps mud from getting into it, the fresh air or combustion air inlet has to be in a similar location to the exhaust so they both have equal pressure, inside the trunk won't do it has to be somewhere outside.
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I never thought of it that way but youre right. I wasnt thinking combustion air , I was thinking that air was coming in the car. The exhaust deflector is there I just have to extend the intake
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there is a j shaped tube that looks like its supposed to extend the intake into the wheel well. Intake right beside exhaust??
No, the end of the J hooks around the inner fender to draw air up by the steering shaft. Note, there are two versions of this J pipe. One has only one curve (will sit flat on a table), the other has an extra bend in it to extend the opening forward. If your car is lowered, you MUST use the latter, otherwise the J pipe can interfere with the tie rod at full left turn lock.
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I need to get the hose or pipe that connects the j tube to the heater before I can do the final assembly. Im thinkin short piece of 1 inch silicone hose should work
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Originally VW used the thin paper tubing, just like what's used to connect your heater channels to the heat vents in the bottom corners of the windows. There should be pieces of this at the swap meet coming up.
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I never would have thought it would be so hard to get that tubing but apparently nobody makes 1 inch.i used silicone heater hose. The heater seems to be operating properly but I havent been driving the car this week. Its -20 in the north okanagan and im 5 minutes from work.just easier to drive something newer. Still need to find the on/off control rod to have everything complete. For now a chunk of welding rod works but I would like to make it proper
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Search is your friend for the hose:
German Supply has the hose new -
http://www.germansupply.com/home/customer/product.php?productid=17466&cat=&page=1
And a local fellow, well known on this site, has it used -
http://www.thesamba.com/vw/classifieds/detail.php?id=1566775
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the hose is dealt with, its the control rod that's the issue now.thanks though
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Here are a few threads from thesamba that may be of help:
http://www.thesamba.com/vw/forum/viewtopic.php?t=314546&highlight=eberspacher
http://www.thesamba.com/vw/forum/viewtopic.php?t=446965
http://www.thesamba.com/vw/forum/viewtopic.php?t=344173
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Control rod look like this?
http://www.thesamba.com/vw/classifieds/detail.php?id=1563572
Looks like it would be pretty easy to make as well.
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yup. it is easy to make. ive already made one but would like to find an original just cuz it wouldn't look out of place as the heater is original to the car.
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This may sound like a dumb question but the on/off switch has 3 positions. Obviously off and on but when u pull the control there is 2 detents. The fan speed doesnt seem to change between 1 and 2 which makes sense if it produces the combustion air. What are the 2 detents?