Making Espar-go

Zeta · 08-09-2011, 05:48 PM

The Espar D4 in my rig never worked well. Usually these heaters carbon up from being run too cool or from high altitude use, so I bought a new atomizing screen and glow plug to repair this issue. I also bought one of the very cool solid state altitude compensating devices Espar sells.

I used these in my TDI Syncro builds many moons ago and know they work well providing the proper fuel ratio at nearly any altitude. My rig had the dual pump set-up assuring the mixture was never right.

When I pulled the glow plug and screen, I noticed they were spotlessly clean--ie. no carbon. This indicated a fuel starvation issue. We all know the crap about not being able to run the furnace with less than 1/4 tank--not sure what to do about it--but my tank was nearly full, yet there was no fuel at the Espar pump. My thesis is that when the fuel tank is run down, it creates a siphon effect that pulls the fuel from the Espar circuit leaving the pump dry. To cure this issue, I installed a small plastic fuel filter in the pump inlet circuit.

This will create a reservoir of fuel for the furnace, but will break the siphon effect if that is the issue--we'll see.

Once I supplied some fuel to the pump, it fired right up. So when this tank runs down, I expect to see a supply of fuel in the filter that will feed the furnace until it can pull in more from the tank.

Z

Zeta · 12-21-2011, 02:47 PM

*Update*

The fuel filter did what I hoped--it created a break for the siphon from the main tank so there's always a small reservoir of fuel for it to at least start on. I still have the problem though. If I run the tank near empty, it draws the fuel from the heater(s) circuit, making them have to prime every time they run. Usually they don't prime and I have to get under the van and prime them--ahem--manually using a length of fuel line attached to the heater pump's fuel line and then suck on it until fuel flows into the aforementioned filter. Diesel tastes terrible BTW.

Yesterday I added a check valve as close to the fuel tank as possible. This keeps the heater circuit from siphoning--at least to the check valve. The heater ran flawlessly all night. EVERY time the heater hasn't worked, it's been because of fuel starvation--no overheating, underheating, carbonning etc..

This spring I'm gonna pull the tank and put the check valve in the Espar fuel pickup in the tank. I'm also going to extend the pickup closer to the bottom of the tank to eliminate the issue of not being able to run the heaters with less than 1/4 tank of fuel--which I hate.

Z

mjeffrey · 12-21-2011, 04:21 PM

Great info, thanks for posting it. I'll copy your check valve idea when my Espar comes back from service. Maybe it was just fuel starvation this whole time!

Cheers,
Mike.

**daveb** · 12-25-2011, 04:37 PM

Too bad there isn't a fuel primer bulb (like on an outboard motor) somewhere on the lines. With that said, why do some have problems with this and some don't? Is it when the van sits with less than a quarter tank that causing the problems?

I have only ran it below 1/4 once but it finally started after I fill the tank up.

The big problem I had was the Hydronic being filled up with dirt.

Zeta · 12-25-2011, 05:04 PM

I bought a primer bulb and may install it, but not looking forward having to get under the van to do the priming. Gonna fix it right this spring.

Z

http://www.tomsinclair.net

mjeffrey · 02-23-2012, 05:18 PM

Hi Zeta - do you recall the diameter of the fuel line at the fuel pump? I'd like to pick up these same parts (primer bulb, fuel filter / check valve) - the Espar manual says it uses 2mm fuel lines, which is a bit bigger than 1/16". Does that sound right?

Thanks very much!
Mike.

Ketcham · 07-29-2012, 10:19 PM

Tom,

I am dropping my tank this week to address other issues. I am going to deal with this as well for both my Espar and my Webasto stove. The latter seems to have the issues you have here...fuel starvation and air entrainment. What mods did you end up doing and how are they working for you?

Zeta · 07-30-2012, 03:55 PM

Quote:

Originally Posted by Ketcham

Tom,

I am dropping my tank this week to address other issues. I am going to deal with this as well for both my Espar and my Webasto stove. The latter seems to have the issues you have here...fuel starvation and air entrainment. What mods did you end up doing and how are they working for you?

I haven't done anything with it since the post above--so much else to fix on these things. The filter made a worthwhile difference so if the furnace hasn't been used in a while it will usually start after two tries, and fires immediately if it's been used recently. I located the check valve as close to the tank as possible, but it didn't seem to help.

I'm still gonna pull the tank to install an AirDog II, and plan to change the way the Espar draws fuel.

Z

Ketcham · 07-30-2012, 04:03 PM

I am doing the airdog 2 now. My issue more is the webasto cooktop...love it but if not used for some time or if the tank is low, it entrains air and takes several attempts to light...45 min or so. Painful. My mechanics are not sure what to use for parts, so I am giving them ideas from your posts.

I would install a oneway valve and possibly priming bulb for both systems, if doable. If the priming bulb causes more resistance, then it would not work.

This is all easy to reroute and deal with since the airdog is an entirely different system. Custom bracket needs to be made for the airdog though.

-j

Zeta · 08-02-2012, 05:30 PM

I looked at one of these:
http://www.mkmcustoms.com/sinisterfuelt ... QgodDgIAPA

Would make fuel pick-up for the AirDog and Espar much better. Plus, the tank doesn't have to be removed. Looks like it hangs way down though.

Z