dirty hands
New Member
**** yeah.
Night.
Night.
dirty hands
New Member
Ok, Ive thought hard about the fuel delivery pump and youre detailed information about the delivery pump operation CharlesY and (as always) answers raise more questions. Hope you dont mind me pursuing these answers in this forum. Pos, if Im in danger of taking this thread away from your original post please accept my apologies, I can raise it as a new thread.
Veg oil tank
!
Veg oil Filter
!
Valve Select Manifold -- Heat exchanger -- Injection pump
!
Diesel fuel filter
!
Fuel delivery pump
!
Diesel tank
The land rover runs with no noticeable difference to performance when it switches over to veg oil. I can only assume at the moment that the fuel delivery pump on the diesel path cant be working. I will of course be checking the operation of the delivery pump. It does pump via the manual lever as I had to bleed the fuel system when I plumbed to veg oil kit in.
A quick solution would be to change the configuration to
Veg oil tank
!
Filter
!
Valve Select Manifold -- Fuel delivery pump -- Heat exchanger -- Injection pump
!
Diesel fuel filter
!
Diesel tank
Heres the first question: Where the delivery pump is at the moment it is sucking / pushing the fuel through the filter. Is it capable of correct operation in the new configuration where its sucking / pushing either the veg oil or diesel through the system after the filters?
Bye
Veg oil tank
!
Veg oil Filter
!
Valve Select Manifold -- Heat exchanger -- Injection pump
!
Diesel fuel filter
!
Fuel delivery pump
!
Diesel tank
The land rover runs with no noticeable difference to performance when it switches over to veg oil. I can only assume at the moment that the fuel delivery pump on the diesel path cant be working. I will of course be checking the operation of the delivery pump. It does pump via the manual lever as I had to bleed the fuel system when I plumbed to veg oil kit in.
A quick solution would be to change the configuration to
Veg oil tank
!
Filter
!
Valve Select Manifold -- Fuel delivery pump -- Heat exchanger -- Injection pump
!
Diesel fuel filter
!
Diesel tank
Heres the first question: Where the delivery pump is at the moment it is sucking / pushing the fuel through the filter. Is it capable of correct operation in the new configuration where its sucking / pushing either the veg oil or diesel through the system after the filters?
Bye
It depends on your Filter head - the casting the fuel filter fits onto.
IF, and it is an IF, the filter head has a air-separation vent built in then you MUST PUSH fuel through it, and must NOT suck fuel through it.
If you plumb it
tank>>>filter >>> lift pump >>>> injection pump
for either or both of the fuels, the air bleed vent in the filter head will let a small but annoying amount of air IN among the fuel and the performance will suffer.
Some filter heads don't have the air-bleed in them, but I think most of them do.
CharlesY
IF, and it is an IF, the filter head has a air-separation vent built in then you MUST PUSH fuel through it, and must NOT suck fuel through it.
If you plumb it
tank>>>filter >>> lift pump >>>> injection pump
for either or both of the fuels, the air bleed vent in the filter head will let a small but annoying amount of air IN among the fuel and the performance will suffer.
Some filter heads don't have the air-bleed in them, but I think most of them do.
CharlesY
dirty hands
New Member
Thanks CharlesY
I looked at the filter housing when I was pondering about the injector bleed off lines. If I remember correctly the banjo on the top of the filter housing has the bleed off line from the injectors passing through horizontally to the return to main tank line. The bolt that holds the banjo on is hollow and does have a pin sized hole half way down the shaft which I assumed bled any air back into the filter. But this is on the return side of things.
I didnt notice any other bleed points but I wasnt looking inside the filter/housing just the injector bleed lines.
I think I need to dismantle the filter/housing and peek inside. Unless you already know, in which case I will bow to your expert judgement and still dismantle the filter / housing.
Thanks
Bye
I looked at the filter housing when I was pondering about the injector bleed off lines. If I remember correctly the banjo on the top of the filter housing has the bleed off line from the injectors passing through horizontally to the return to main tank line. The bolt that holds the banjo on is hollow and does have a pin sized hole half way down the shaft which I assumed bled any air back into the filter. But this is on the return side of things.
I didnt notice any other bleed points but I wasnt looking inside the filter/housing just the injector bleed lines.
I think I need to dismantle the filter/housing and peek inside. Unless you already know, in which case I will bow to your expert judgement and still dismantle the filter / housing.
Thanks
Bye
dirty hands
New Member
Im pretty sure its there so that air from the injector bleed off lines can purge harmlessly into the top of the filter? The hole in mine was blocked. I unblocked it and it didnt make any difference to anything.
The veg kit I have said that the system needs to be a re circulating fuel system and air leaks can not be tolerated. To me It looked like it was a re circulating system as any air in the line would purge at the filter top. But again just my interpretation of the Haynes (brief summary on how to dismantle a Land Rover) manual.
Hang on a second, if the hole in the hollow bolt does bleed air into the top of the filter if i have the delivery pump sucking fuel through the filter it will suck air in at this point.
Yeah, like Pos said. Does it need to be there?
My head hurts....
The veg kit I have said that the system needs to be a re circulating fuel system and air leaks can not be tolerated. To me It looked like it was a re circulating system as any air in the line would purge at the filter top. But again just my interpretation of the Haynes (brief summary on how to dismantle a Land Rover) manual.
Hang on a second, if the hole in the hollow bolt does bleed air into the top of the filter if i have the delivery pump sucking fuel through the filter it will suck air in at this point.
Yeah, like Pos said. Does it need to be there?
My head hurts....
dirty hands
New Member
OK, Ive thought long and hard about this and drawn a picture of the proposed configuration.
IF I can take the return from the injector bleed off line and injector pump return and not return it via the diesel filter but instead return it via the valve manifold return AND I ensure that no air can be sucked in via the diesel filter i.e. plug all inputs / returns on the diesel filter apart from the diesel in / out. I think the lift pump will suck the fuel from whichever tank is selected.
As stated earlier, Im an idiot. I think I understand what Im doing but a second opinion would be welcome. Can anyone spot any flaws in my cunning plan?
Ta
IF I can take the return from the injector bleed off line and injector pump return and not return it via the diesel filter but instead return it via the valve manifold return AND I ensure that no air can be sucked in via the diesel filter i.e. plug all inputs / returns on the diesel filter apart from the diesel in / out. I think the lift pump will suck the fuel from whichever tank is selected.
As stated earlier, Im an idiot. I think I understand what Im doing but a second opinion would be welcome. Can anyone spot any flaws in my cunning plan?
Ta
Attachments
discomania
Well-Known Member
discomania
Well-Known Member
dirty hands
New Member
Firm but fair. Many thanks. The fuel lines have not arived yet. So I've not re plumed it yet.
I realy do appreciate the help. All the advice on here (either current or old) has been of the highest quality.
It must wear you down......
dirty hands
New Member
Ok, im in danger of over egging the detail here, but its the only way mi monkey brain can digest the info. Another picture I fear
.
You quite clearly stated on a few occasions (sorry about that) that the configuration should be
Diesel oil
!
ORàLift PumpàFilteràInjection pump
!
Veg oil
I was reluctant to do this due in part to my lack of understanding the land rover fuel system and my desire to keep the duel system as separate from each other as possible.
It is now quite clear that I cant do this as there is only one lift pump and it needs to pump (finally sunk in and accepted).
Looking at the diagram, I think the heat exchanger needs to be before the Diesel filter as the veg oil will need to be thin (hot) so it will go through the filter as well as diesel does. I suspect you may tell me that the lift pump will struggle pumping cold veg?
If this is true and the heat exchanger needs to be before the lift pump then by the time the veg oil gets through the lift pump and through the filter it will have cooled down and the injection pump will squeal and eventually fail from lack of lubrication. Time for a lie down again .
You can tell me to feck off if Im being a pain but I think youre all professional enough to humour the numb nut with the veg oil fetish .
Sorry, thanks, sorry, thanks, sorry, thanks . **backs out slowly from the forum**
You quite clearly stated on a few occasions (sorry about that) that the configuration should be
Diesel oil
!
ORàLift PumpàFilteràInjection pump
!
Veg oil
I was reluctant to do this due in part to my lack of understanding the land rover fuel system and my desire to keep the duel system as separate from each other as possible.
It is now quite clear that I cant do this as there is only one lift pump and it needs to pump (finally sunk in and accepted).
Looking at the diagram, I think the heat exchanger needs to be before the Diesel filter as the veg oil will need to be thin (hot) so it will go through the filter as well as diesel does. I suspect you may tell me that the lift pump will struggle pumping cold veg?
If this is true and the heat exchanger needs to be before the lift pump then by the time the veg oil gets through the lift pump and through the filter it will have cooled down and the injection pump will squeal and eventually fail from lack of lubrication. Time for a lie down again .
You can tell me to feck off if Im being a pain but I think youre all professional enough to humour the numb nut with the veg oil fetish .
Sorry, thanks, sorry, thanks, sorry, thanks . **backs out slowly from the forum**
Attachments
GRUNT
Well-Known Member
I know as much as you about it, but:-
A. If you want to keep the two cicuits separate why not bung an electric pump in there somewhere.
B. If you get the veg oil hot enough to make any difference then I would have thought it would keep its heat long enough to get through the IP, specialy if the heater is as near as possible to the pumps and filter. Unless of course your running the pipes round by Aberystwyth and back.
A. If you want to keep the two cicuits separate why not bung an electric pump in there somewhere.
B. If you get the veg oil hot enough to make any difference then I would have thought it would keep its heat long enough to get through the IP, specialy if the heater is as near as possible to the pumps and filter. Unless of course your running the pipes round by Aberystwyth and back.
timberjock
Active Member
you will find the veg oil won't seaze the pump through lack of lubracation due to it being oil though may block it if it got clod enough.
dirty hands
New Member
Its still got to be hot (about 70c) so the veg oil is thin enough (as thin as diesel) to get into all the small places that it needs to in the injector pump.
Thats my understanding anyway. Otherwise why heat it up at all?
Thanks for the answers, I won't be doing anythin untill the weekend so plenty of time to ponder and drink tea...
The little pinhole in the banjo nut on top of the filter head has bugger all to do with anything coming back from the injectors! THINK !! EXAMINE the order of the components!!!
The FUEL is in the tank. So too is a whole lot of AIR, and it is all sloshing about, especially when the fuel level is sort of low. The lift pump SUCKS fuel (and probably some and bubbles of air) into itself, and then PUMPS the fuel to the fuel filter. The fuel in ther filter is thus under a little pressure (3 - 4 psi) and as the fuel slowly RISES after passing through the filter element) any air bubbles will rise fasters than the fuel, and reach a little chamber at the top, in the very highest part of the filter head. This is where that pin-hole banjo is. The air bubble pass through the pinhole easily, and returns to the tank with the spill-over from both the injectors and the injection pump. As soon as there is no air left in the filter head, neat fuel reaches the pinhole, and from then all a tiny amount of fuel passes through the pinhole and back to the tank. A small hole will pass a lot of air, but only a little fuel.
THEREFORE, it is essential that the correct order of components is used.
TANK >>> LIFT PUMP >>>> FILTER >>>> INJECTION PUMP >>> Injectors.
If you set it up
TANK>>>FILTER >>> LIFT PUMP>>>> etc, then you are guaranteeing that air WILL be drawn INTO the fuel, and you have disabled the self-bleeding ability of the system.
OK?
CharlesY
The FUEL is in the tank. So too is a whole lot of AIR, and it is all sloshing about, especially when the fuel level is sort of low. The lift pump SUCKS fuel (and probably some and bubbles of air) into itself, and then PUMPS the fuel to the fuel filter. The fuel in ther filter is thus under a little pressure (3 - 4 psi) and as the fuel slowly RISES after passing through the filter element) any air bubbles will rise fasters than the fuel, and reach a little chamber at the top, in the very highest part of the filter head. This is where that pin-hole banjo is. The air bubble pass through the pinhole easily, and returns to the tank with the spill-over from both the injectors and the injection pump. As soon as there is no air left in the filter head, neat fuel reaches the pinhole, and from then all a tiny amount of fuel passes through the pinhole and back to the tank. A small hole will pass a lot of air, but only a little fuel.
THEREFORE, it is essential that the correct order of components is used.
TANK >>> LIFT PUMP >>>> FILTER >>>> INJECTION PUMP >>> Injectors.
If you set it up
TANK>>>FILTER >>> LIFT PUMP>>>> etc, then you are guaranteeing that air WILL be drawn INTO the fuel, and you have disabled the self-bleeding ability of the system.
OK?
CharlesY
SVO = straight vegetable oil isn't like putty!
The tank and lift pump will handle it fine.
In the winter you might want to thin it with some kerosene (28 second heating oil) or use it 50-50 with pump diesel, but otherwise forget all about heaters and problems like that. It isn't required.
CharlesY
The tank and lift pump will handle it fine.
In the winter you might want to thin it with some kerosene (28 second heating oil) or use it 50-50 with pump diesel, but otherwise forget all about heaters and problems like that. It isn't required.
CharlesY
