Yet Another L400 Conversion

[jessef]

a walbro in line fuel pump solved my WVO surging after long highway drives and at idle.

Installing the fuel pump does an interesting thing - same as advancing the timing.

You'll find that an 8psi fuel pump will push veg along at 3-4psi so a higher rated pump 9-11psi is good ONLY for veg. Using this pump for diesel would be too much pressure for the IP so an on/off manual switch for the pump is a good idea.

Make sure you get one that flows freely if it dies. Nice conversion

[northriver]

Thanks for the feedback jfarsang and rezdiver!

My initial system uses a 1/2" fuel line from the WVO tank to the WVO fuel filter ... and then 5/16" from the filter to the injection pump ... I am not sure if bumping it up to 5/8" where it is 1/2" would help any more?

I did bump the idle screw adjustment up already (100 revs?) ... it seemed to help somewhat. I am hesitant to increase it much more as it will idle that much higher on diesel.

I like the idea of a fuel pump that allows flow if it fails ... that or a hotfox may be my next investment!

[northriver]

Following up on the stalling problem I mentioned ...

When I got home I drove the van into the shop and the next day I got underneath it and looked around. I found two locations where the fuel line leading to the injection pump had collapsed on itself, restricting the flow of WVO. Both restrictions occurred where the line curved to change directions. I did not think these bends were significant enough to do this, but obviously the combination of suction from the pump and the bend had collapsed the line. This leads me to wonder if I got the best fuel hose for a diesel … a thicker, stronger wall would help prevent this problem. Regardless, I re-routed and fixed the collapsed sections.

I also decided to clean the injectors while I had it in the shop. I had noticed more black smoke towards the end of the trip when starting and during quick accelerations … from what I had read fouled injectors (injector coking?) can contribute to this problem. (WARNING: there are little parts in the injectors … do this work over a clean workbench unless you want to be searching a dirty shop floor for these tiny parts … maybe I should just clean the shop floor?) From a visual inspection two of the fuel injectors were clean and two were fouled; I disassembled and cleaned all of the injectors (the Australian Delica website has an excellent PDF on doing this).

Happily, the van ran much better after this tune up; less smoke, better sound and no idle issue on WVO! Unhappily, after about another 500 km’s running on WVO the stalling on idle issue was back … this was not a happy moment. I put the van back in the shop expecting to find another collapsed hose … only there weren’t one. So, I pulled and cleaned the injectors again … one of the injectors did look fouled, the balance looked fine. I have gone from thinking that I had a fuel starvation issue to thinking that the WVO may not always be hot enough going into the injection pump. This initially surprised me as I have a heated filter and an in-line heater right before the pump. However, the heater is switched to shut off by a thermal sensor (attached to one of the injector feed lines) that shuts the heater off when the oil is hot enough. When I think about my stalling problem it seems to occur at cooler outside temperatures (below freezing temperature) after the van has been running for a while (hot engine, hot coolant). I am now wondering if the sensor is shutting the heater off too much in colder weather? Causing fouled injectors and leading to the stalling problems?

Not sure if I have correctly identified the problem, but again after cleaning the injectors the van is running fine on WVO … no stalling at idle. I have also disconnected the thermal sensor to see if this helps … we will see if I have solved this problem in another 500 km!

I was prepared to install an in-line fuel pump beside the WVO tank to push the oil to the injector pump (already purchased), but I have not done this yet as I am not convinced this is my problem given what I have found out.

[BCDelica]

One piece of advice I'd read and followed was using the highest quality, and largest ID workable, when installing WVO supply lines. Also having helped with many a troubleshooting session on a WVO vehicle, finding that most problems occured from issues with WVO lines, commonly a suction related reduce in flow or air entering the system at a hoses end.

Also have changed out thermocouples for exactly the same cold weather reasons you describe, finding one from an appliance store with a much higher reset temperature, turning the inline heater back on earlier solved my winter stalling problem. That new thermocouple only switched off at 2 c warmer, so I think it was the switching back on at a higher temperature that assisted with my issue.

I also noticed increasing smoke at first, with dirty injectors and glow plugs after just months of WVO driving (funny enough her Delica far more than mine with the same system). After regularly adding 500 - 300 ml of acetone to every 200 liters of WVO, this was great reduced - we could drive our Delicas' on WVO for over a year with no increase in exhaust smoke!

So, how about a trip report of your cross country WVO trip!

[BV1]

Thanks for sharing your experiences Northriver, its very informative for me, doing a swap myself later this year :)

Steve

[jessef]

did you go with an inline pump?

[fmande]

Following up on the stalling problem I mentioned ...



I was prepared to install an in-line fuel pump beside the WVO tank to push the oil to the injector pump (already purchased), but I have not done this yet as I am not convinced this is my problem given what I have found out.

I can't suggest any help with WVO but I am familiar with the injection pump and injectors.
I just pulled my injectors apart and removed the carbon.
The concern I have is the installation of a second assist pump.
Here in Australia we have had a number of engines destroyed when the fuel pump seals failed and the assist pump filled the sump with diesel.It helped in the begining but assisted in destroying the engine
I would be very cautious when installing this modification.
Good luck with it

[jessef]

The inline pump is used to push the thick wvo from the tank to the injection pump. It's different than using diesel as a fuel source.

When using wvo with the stock fuel lines, the psi rating drops because of the thicker fuel. This can cause surging as the injection pump cannot keep up. The inline pump brings the psi level up so that the injection pump is not over working itself that eventually may lead to ip failure.

[fmande]

The inline pump is used to push the thick wvo from the tank to the injection pump. It's different than using diesel as a fuel source.

When using wvo with the stock fuel lines, the psi rating drops because of the thicker fuel. This can cause surging as the injection pump cannot keep up. The inline pump brings the psi level up so that the injection pump is not over working itself that eventually may lead to ip failure.

Thanks for the explanation Jesse.
We have WVO here but don't have the low temperatures you have.
The problem I have noticed is the viscosity of the fuel.
It has be reported here that alternate fuels are destroying fuel pump seals.(so does our diesel fuel)
Also the age of the pumps need to be taken in to account.
There still is the posibility of failing fuel pump seals.
It is just an opinion.

[northriver]

I have not been on the site in a long time ... just thought I would post an update about our WVO conversion.

I had actually planned to put a 2nd pump in the fuel tank to assist with oil flow (as described above). I purchased the pump but never got around to installing it ... I was never really thrilled with doing this as a solution.

I am thrilled to report that the system has been working properly for months now without the addition of the 2nd fuel pump.

I did do a number of other things, including; replacing the fuel injectors and insulating the WVO lines in the engine compartment (on the theory that the oil was losing too much heat). I am not really sure what finally eliminated the problem ... the most likely one was replacing the injectors (I do not think the insulation was of much benefit), but I cannot say that the day after the injectors were replaced the stalling issue disappeared. If I remember correctly the system sorted itself out after the first filter change with the new injectors in place. I am not sure why the combination of new injectors and a new filter made the ultimate difference.

Regardless, I am happy to say that the WVO system has been working properly with no stalling for some time now. Our only maintenance has been replacing the WVO filter when we notice the engine starting to fade when on WVO ... this seems to work out to about 10,000 kms but I have not tracked it too closely.

[TardisDeli]

Hi Chris and Sandra, nice to see you post again, glad you survived the winter with your wvo delica. Did you have the block heater running, and did you check the amperage draw when cold to determine if life off-grid would support it? Some delii owners in northern BC have switched to gas delicas and sold the deisel delica because short of building a wood fire underneath the delica (that is a joke, readers, dont' light a fire underneath a gas tank - kaboom) it was difficult to keep the system warm overnight off-grid.

Christine.

[northriver]

The short answer is no ... I am not sure what the amperage draw on our engine block heater is.
I seem to recall when I installed the unit that it was a pretty small unit (500 watt? ... I honestly do not remember).

When we do use the heater we turn it on a few hours before going somewhere, this seems to give it enough time to warm the engine sufficiently ... so it has not been a huge consumer. Last winter I would be surprised if we used it more than twenty times (again, a guess) ... we did not use it if it was only a few degrees below zero.

I am currently working at reducing our home electrical energy consumption prior to going off-grid ... it is amazing how much we were using without thinking about it. We have already reduced our consumption down to about 24 kWh/day starting from about 40 kWh/day by doing things like disconnecting a yard light and paying more attention to what is on and when. The eventual target is 5 kWh/day ... I guess the block heater might be significant at that level ... although I never thought of lighting a fire under the engine!

When we used to operate our log home business ... we did occasionally put a propane flame (called a tiger torch) under the forklifts in extremely cold weather prior to starting them to warm the engines ... talk about stressful.