312D veg oil and limp home

[Hibbo]

I havn't fitted a pre filter before the main filter and i don;t think there is a stock one there?

There should be, all Merc diesel I've seen have one. On the om602 (which I think your van uses, 5 cylinder?) it is a little in-line filter on the rubber pipe connecting the solid fuel pipe to the lift-pump.

 

[Hibbo]

Found a pic of the prefilter cut open from my 300D after its first tank of veg. Dread to think what the main one was like.

If you haven't got one, fit one! It'll save you a few canisters.

Do NOT underestimate 1) How much crap your fuel system accumulates, and 2) The cleaning power of the MIGHTY Veg oil!

I'm off to do to my kidneys what veg did to my filters!

 

[Bill312D]

unless its veyr well hidden thenthere is nothing like that between the main filter and the tank, I might put a little in line filter in there though i have a spare one. although I hate mesing with that ****ty plastic hose.

 

[Bill312D]

Soanyone know what filter will fit? Mercedes will probbaly chrage me to ask them...

 

[premmington]

good reply

good reply, from last post....

Vegetable Oils. Seed oils are not particularly "good" for most modern diesels, in fact they can be downright destructive for common rail set-ups. Seed oils contain no lubricity agents. Bosch EDC pumps, in common with the Lucas pumps, fuel and hence lubrication is cut off to the rotorhead during conditions of overrun (engine braking). Any restriction in fuel supply to the pump, for instance a partial filter blockage could also cause damage to the pump, through lubrication starvation. Early models were quite prone to failing, within the distributor rotor assembly, which has been*through three different updates since the pump was first made. Later pumps are therefore more reliable in this respect. Seed oils also adsorb water from the atmosphere and as a consequence, there is a greater risk of problems in cold weather due to waxing. They tend to have a higher viscosity than DERV and need to be passed thru a pre-heater, prior to being fed thru a calibrated diesel injection pump (Ford Endura DE-Di engines have a nice modular inline heater fitted to them). If HM C&E do catch you with seed oil in your tank and you cannot prove that you have paid the duty on it (retrospective duty), they have a very simple calculation that they use. They will take your average mileage from MOT certificates (VOSA computer) and charge you a year's worth of duty, they also may confiscate/impound the vehicle. *It is a simple matter to check, all that is required is a hygrometer. *All UK DERV is Ultra Low Sulphur Diesel (ULSD) and is formulated with a very tight specific gravity tolerance at the refinery. If the SG does not match what it should be on the list they carry, you're nicked.
Red diesel. One other word of warning. *If anyone is thinking of buying "cheap" diesel, don't bother. It is more than likely rebated or red diesel that has had the dye stripped out. *Forget all those fanciful tales of pouring it through fuller's earth to remove the dye, it's just not true. *What they actually use is Oleum (fuming sulphuric acid) & cat litter (the active ingredient contained in it, that neutralises the smell of cat urine also does wonders at removing dye), lime or cement powder, then filter it again thru cotton wool or a one micron industrial steam filter. *This not only strips the dye but also all of the lubricity agents and all the other additives that are added to DERV, anti-wax & anti-foam. *The resultant toxic sludge is then dumped at the side of the road, with all the resulting environmental impacts. *Oh... and because red diesel has a different SG to DERV, the hygrometer trick still works equally as well. Most HM C&E roadside testing (dipping) used to be done with a clear squeegee bottle and a pipe, they would simply take a sample from your tank, look at the colour, either nick you on the spot or put it back in the tank and let you go on your way. But now they have very neat, small portable mini labs to test your DERV at the roadside. Kerosene (28sec oil) is commercial/home heating oil which is known as 'kero' or 'paraffin'. It is straw/orange in colour, very clean burning (has a very low sulphur content) and economical to use, however it contains no lubricant and is thus not suitable as fuel for engines. Even when mixed 50/50 with DERV, HM C&E roadside checks can still detect it, using their new high-tech mini labs.
Some people fit a second "hidden tank" so they can use red derv undetected. Carefully routing the supply/return pipes out of view. Only to be caught because the HM C&E have dipped there main tank and its been green derv they have pulled out, reason being if derv stands about it absorbs water "hygroscopic" then if left for a long while green-blackish microbes grows in it. HM C&E staff are dipping cars & light vans all day & if they can't get a pipe down your fuel filler tube, alarm bells will ring.
Red diesel in a un-tampered state, will not harm a road going engine, most damage to pumps related to running on red diesel is caused by water or other contaminants being mixed with the fuel. The source normally can be traced back to dirty fuel containers/cans being used to store & transport the fuel. We have over the years removed some vile looking fluids from fuel tanks over the years! Red diesel stripped of its dye & additives will wax in cold weather, foam causing problems filling small auto fuel tanks and may wreck injection pumps due to the removal of lubricity agents.
LPG is the only viable cheap fuel at the moment, that is until the Government raises the tax on it. I never think they will. As it is used for domestic heating, its going to be tax free, with a lower VAT & duty rating. HM C&E staff can't sample a car gas tank easily, they just are never going to be able to regulate it. Someone somewhere will be having gas delivered for there house boiler at a cheaper price & pumping into their car as a fluid, using industrial forklift filling equipment & pump.**A point of interest is: in Europe, adapters are available to refill 13kg 19kg 49kg propane bottles via auto-gas-pumps (its a cheaper way of buying the gas than exchanging empty for full bottles).
Diesel & water emulsions. Elf and Lubrizol have plans to sell diesel & water emulsions under the trade names "Aquazole" and "Purinox" respectively for use in closed commercial fleets. As far as is known these emulsions have not been tested with inline fuel injection systems. The rumour in the trade is, Bosch are being very quiet about the issue. The advantages quoted about by the fuel companies being; emissions can be immediately reduced for a limited period without having to take any other measures. My initial thoughts were, water is cheap! The disadvantage is, diesel & water emulsion fuel is, its not suitable for more modern fuel injection systems. For that reason, the fuel cannot be sold on the open market. Diesel & water emulsion fuels have loads of additives such as, emulsifiers, anti-corrosive additives, anti-freeze, lubricant and biocides to prevent the growth of micro-organisms. I suspect the fuel companies will be very quiet over new fuels. As its coming to light now, pre 1998 low sulphur diesel did not have enough lubricant in it and was the cause of wear related problems on distributor type fuel injection pumps, which are lubricated by fuel. They have raised the lubricity value of EN590 fuel to 460um to correct this. Bosch recommends the use of diesel fuel with a lubricity value no less than 400um.

http://www.remmington.plus.com

 

[Bill312D]

Right, I changed the filter ealry in the week after running it right down out of veg to make sure the maximum amount of crap from the tank was removed, and everything seemed to be running fine for about 300 miles. then today i just got on the motorway accelerated to 85 and was settling down to that sorta speed and suddenly allt he power dropped wouldn;t rev over 3800 etc etc, same as before. thought it could be another filter, so went and bought 2 filters and fitted one, and then after another 30 miles or so, it happened again. And was cured by turning off the ignition and turning it back on. Any ideas?

 

[Bill312D]

so could it be the problem i first mentioned about the pump sucking from itself causing strange pressure readings? or is there another simple thing i can do?

 

[Bill312D]

http://forums.mercedesclub.org.uk/showthread.php?p=169187#post169187 now this has happened, not happy.

 

[Bill312D]

anyone got any ideas then, i dunno what to do next if th NRV doesn't work

 

[Cnics]

To be fair, you seem to have a similar problem to what i've been having recently, mine is a cdi model however i know other people who have had similar issues on the older models. I've been through a few suggestions, including turbo related things, it is very possible that the fact you are on veg oil is purely a coincidence.

Or maybe my problem is fuel related. I have this permenant "no power" problem at the moment which i think is related to something else on the turbo side, but my intermittent problems (which could be cured by a switch off and on) may be fuel related, i'll get this issue sorted and give it a fuel filter and associates, no harm in doing it anyway.

Rob

 

[Bill312D]

Yeah, I am gonna give this non return valve a go to ammend any odd pressures at the pump returnthen fi that doesn;t work gonna have to go down the MAF etc route. 312D's don;t have MAF's do they? its something else I think, a little help please.

 

[Bill312D]

I tok the van to the local independent today and a fuel pump fault came up he couldn;t find a problemw ith the pump itself so it must be being affected byt he smart veg kit in some way...which leads me tot hink fuel pressure...what else could it be ? I have to wait a hwile for the NRV as Royal FAIL seem to have lost it.

 

[Hibbo]

Re-plump the fuel system so there is no looped return.

 

[Bill312D]

hasn;t faulted for a while, since the coees were cleared and it was maintiaing 90mph for a fair while on the way back form Wales. although un looping the return would probably fix the problem if fuel pressure was/is the cause it would also massivley extendwarm up times for the fuel and require another 3 way valve...may have to do it though if the problem manifests itself again.

 

[Bill312D]

Just thought i'd update this thread incase anyone finds it on a search in the future I cleaned up the air flow sensor in one of the induction pipes. I also noticed the EGR pipe was leaking from a crack in the bendy looking bit just above where it joins with the other peice of pipe from the manifold. after replacing the section of pipe the problem has stopped occouring,it has gone into limp home once since and I don't know why i quick switch off and on again cured it and it hasn't happened again since then.