Eberspacher B2 Rebuild Project

[Ma77]

i have a similar problem with mine

if you just switch the heater on the fuel will cool the glow plug so that it does not get hot enough to ignite the fuel. thus the heater will not start and fill up with fuel.

i fitted a n/c push switch inline to fuel pump so that when pressed the fuel pump stops.

i have to let the pump click a few times so there is fuel in the combustion chamber then push the switch to stop the pump, the glow plug can then get hot enough to ignite the fuel (you can hear it igniting). when it does you let go of the switch, the fuel pump starts again and the heater is working.

this takes about 30 seconds, the glow plug i have is from a newer model heater and has a spark plug element aswell as the glow plug. i have attatched a BBQ/cooker piezo ignitor to this so now the fuel ignites as soon as the plugs sparks...no 30 second wait for the glow plug to heat up.

hope this helps and makes sense.

[thomas.]

3-This thread mentions a two speed blower, I do not believe mine is.

Any help is appreciated,

Pete[/quote] I think what they mean by this is once the heater starts blowing warm air the blower motor kicks up automatically to a higher speed.Although I can't confirm this because I haven't got mine to light yet.I finally got the pump to work after changing the rubber diaphragm.I used one off an old vw fuel pump. I know it's suppose to be 3.5 turns out but mine works better between 2.5 and 3. Bolts should be snugged up tight. If you should try an aftermarket pump the testing method for the correct amount of fuel on the O.E pump is 4.5 cubic centimeters through the main jet in one minute. I haven't messed with mine for awhile , what with other projects and that damn pesky daytime job taking up all the good time.Please post if you have any success.
regards
Tom

[Bruce]

[pete180]

GLow plug slowing the motor makes perfect sense...why didn't I think of that! The 3 speed fans in older vehicles use resisters to drop the voltage.

Regarding the pump flow rate; the pump diaphram is two piece, red and black. The black seemed stiff so I removed just that and the pump clicked away just fine but still could only measure 2 - 3 psi and only a trickle out of the metering jet. Should it trickle or spray? I have yet to measure the flow rate. The pump intakes via the electromagnet and discharges via the spring tension (force). Measuring the spring force and the area of the diaphram I do not quite get to a calculated pressure of 2 psi, so what am I missing?

Thanks everyone!


Pete

[Bruce]

[pete180]

Does the heater work was the question.
The friend who gave it to me said he fired it up on the bench and he thought it did but that was years ago.
The fuel lines were dry rotted and the blower squealed real bad when I first put power to it so I disassembled and went through each component. All seems fine, just need to get the fuel to the metering jet.

Pete

[thomas.]

That's a pretty good tip about the delay switch .I have a toggle switch I'm going to wire in to delay the fuel pump .Although I'm thinking if I had it wired to the car and getting full power from the generator it might light up.But I still want to get it lit out of the car first since others have had success.
My metering jet doesn't come out in a mist but drips gas in a trickle like yours.I think that's correct.
That pump can be a bitch,especially when your testing with raw gasoline and have to keep disassembling to try something different.

[Bruce]

[pete180]

I have not tried the heater yet. As of now the only way I can get some fuel to flow is by removing the black layer of the pump diaphram. I may try this weekend to light the heater off with the pump as is but was hoping for more specific flow info such as:

Does fuel spray or trickle out of the metering jet?

What is the operating fuel pressure?

Someone did give me the flow rate so I will measure and compare. Also someone did mention the fuel trickles so maybe this is normal just seems odd.

Thanks,

Pete

[pete180]

Making some head way.
My fuel pump output through the main metering jet is about 4.5 CC/min.
Glow plug glows red after about 15 seconds.
Fan runs slower while glow plug is energized then speeds up when I disconnect the glow plug.
I interrupted the fuel pump circuit with a switch so I could get the plug hot prior to injecting fuel.

BUT I still cannot get the heater to light off.

If I have run the fuel pump for say 90 seconds without the plug connected (not intentional as I had a bad plug ground) then heated the glow plug could there have been too rich a mixture to allow combustion?

This was the way I ended my heater session about 11 pm last evening...more tonight. And I will check fan rpm with a mechanical tach.


Pete

[pete180]

Still no light off!

I rechecked the fuel flow of the metering jet and it appears to be more like 6 or 7 CC/min as opposed to the manuals recommended 4.5 cc/min.

Checked the RPM and right on spec ~5000 rpm during start up with glow plug in the circuit.

The glow plug glows orange and touching a fuel soaked tissue lights immediately so why no combustion in the burner can?

I tissue tested the intake to the combustion blower and there is positive air flow in the correction direction.

What am I missing?

As said previously I interrupt the fuel pump during start for 30 seconds to let the glow plug get to temp then bring on the fuel. How long should it take for combustion to occur? I let the fuel flow for a minute of so and when I smell fuel shut everything down.

I am using 100LL av gas and once 35 years ago could not get a 2 stroke race bike to run worth a darn so will try tonight with auto fuel.

Any help is appreciated,

Pete

[thomas.]

OK pete 180 ,today was the day . I finally got the damn thing to lite up. Mine was doing the same as yours.Had everything running.Fan;glow plug;fuel pump,and it wouldn't do anything.I was beginning to think heat exchanger was the problem.Anyway here's what I did ( I'm stoked man) I put a switch on the fuel pump to delay the gas, this probably helped the matter.But I think the big solution was I reset the Thermo switch.If you haven't done this you might try it.I took it out a few months back but didn't mess with the setting screw.So it was easy to come out.Turned the screw in until a click then slowly out until another click then back in 120 degrees or 1/3 a turn.When it started making a weird sound it never did before I knew what was about to happen.Well it started blowing enough heat to probably warm up my one car garage.After I shut it down it kept running like it was suppose to but I couldn't remember how to fine tune the thermo switch.Ran back upstairs to computer pdf file .Back down to garage, turned screw back in just a hair and it shut off. Its suppose to run on 3 minutes I think. I also ran a hose from the intake air like it would be on the car.Anyway here's some dangerous looking pictures to some. Didn't leave off any real bad emissions .Not any black smoke.My wife will notice the smell when she gets home from work though.
regards
Tom

[thomas.]

[thomas.]

This is another B2 I bought last fall for an offer I couldn't refuse.It's a 12 volt if I ever need it. It has the missing parts I'll need for the 6volt install.The guy I bought this off of had another eber. from a Thing I wish I would of grabbed up on ebay.I think it went for under $50.Didn't want be greedy i guess.

[pete180]

Tom,
I put some tissue soaked in auto gas in the glow plug and finally got the heater to light off. It worked as advertised meaning dropped the glow plug out of the circuit after about 30 sec. After about 5 minutes the heater cycled off due to the high limit switch opening the fuel pump circuit. After the fuel shut off and the flame went out the fan continued for ~ 3 minutes after shutting off the power on/off SW. I have not been able to get it to light off again and seems the glow plug is not hot enough. There is always fuel in the combustion chamber and the glow plug does glow red (orange) every time tested. Does anyone know how to get in touch with a service person?

Pete

[Bruce]

Measure the voltage at the plug while it's not lighting the fuel.
_________________

[pete180]

Cory,
The voltage at the glow plug is 4V and I believe when I did measure it fuel was not flowing, I will check again tonight. Last time I tried to start the heater I jumpered the glow plug from ~1/3 down the resistor coil and still no light off. Doing this outside of the combustion chamber where I could observe the element it is noticeably brighter orange.

Pete

[jibjab]

I finally got mine to light and now it runs consistently.

I was using a battery charger to make my 12v to the heater.
Although the fan ran fine and the fuel pump acted as it should, my glow plug was not getting hot when trying to test the unit. But the glow plug would test good by itself, outside the unit.

Finally hooked it to a charged battery, and the heater runs as it should. I think the output of the charger doesn't put out enough current to run all the parts together.

Hope this helps someone else.

[Bruce]

[DAVID66000]

Hello I'm french
I own a 1963 option with cox eberspacher b2 with 6V
Can bring me help in restarting
I do not know where to start
it runs but does not relieve heat
[img]https://www.thesamba.com/vw/gallery/pix/[/img]