Author Topic: 1970 beetle gas heater (Read 9452 times)

purple turd · « **on:** January 25, 2014, 12:31:01 PM »

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]

BUSDADDY · « **Reply #1 on:** January 26, 2014, 10:25:34 AM »

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.

owdlvr · « **Reply #2 on:** January 26, 2014, 10:55:25 AM »

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

purple turd · « **Reply #3 on:** January 26, 2014, 03:22:06 PM »

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

BUSDADDY · « **Reply #4 on:** January 26, 2014, 03:24:06 PM »

Quote from: purple turd on January 26, 2014, 03:22:06 PM

............. The fuel pump pumps air but wont draw fuel ..............

A leak in the inlet line or filter will do that.

pittwagen · « **Reply #5 on:** January 26, 2014, 04:06:29 PM »

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.

purple turd · « **Reply #6 on:** January 26, 2014, 05:15:42 PM »

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.

pittwagen · « **Reply #7 on:** January 26, 2014, 05:49:20 PM »

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!

owdlvr · « **Reply #8 on:** January 26, 2014, 06:07:53 PM »

Send me your email and I'll hook you up with the Eberspacher technical manual. It's the Bentley for heaters.

-Dave

purple turd · « **Reply #9 on:** January 26, 2014, 06:16:20 PM »

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

purple turd · « **Reply #10 on:** January 26, 2014, 06:35:42 PM »

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

BUSDADDY · « **Reply #11 on:** January 26, 2014, 06:44:39 PM »

That sounds much earlier than a 70 heater.

purple turd · « **Reply #12 on:** January 26, 2014, 08:54:20 PM »

Even all the holes in the body of the car where the heater is plumbed...exhaust, fan, etc look factory

pittwagen · « **Reply #13 on:** January 26, 2014, 10:05:09 PM »

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?

purple turd · « **Reply #14 on:** January 27, 2014, 08:38:56 PM »

Got it fired....smokes like a bugger.now what

owdlvr · « **Reply #15 on:** January 27, 2014, 08:45:30 PM »

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

purple turd · « **Reply #16 on:** January 27, 2014, 08:58:54 PM »

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

owdlvr · « **Reply #17 on:** January 27, 2014, 09:21:57 PM »

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

purple turd · « **Reply #18 on:** January 27, 2014, 09:43:30 PM »

23042 performance world. Like $50 at mopac.it does pump in pulses but may be too much.

owdlvr · « **Reply #19 on:** January 27, 2014, 10:26:22 PM »

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

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

purple turd · « **Reply #20 on:** January 28, 2014, 06:55:02 AM »

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

BUSDADDY · « **Reply #21 on:** January 28, 2014, 07:18:57 AM »

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

purple turd · « **Reply #22 on:** January 28, 2014, 06:58:13 PM »

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

purple turd · « **Reply #23 on:** January 29, 2014, 09:31:15 PM »

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

BUSDADDY · « **Reply #24 on:** January 30, 2014, 07:30:13 AM »

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.

owdlvr · « **Reply #25 on:** January 30, 2014, 10:09:35 AM »

1 Litre per hour is the BN2 fuel rating.

~16ml per min

-Dave

pittwagen · « **Reply #26 on:** January 30, 2014, 10:00:45 PM »

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.

purple turd · « **Reply #27 on:** January 31, 2014, 04:10:08 PM »

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

purple turd · « **Reply #28 on:** February 02, 2014, 09:28:47 AM »

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

BUSDADDY · « **Reply #29 on:** February 02, 2014, 10:16:12 AM »

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.