GBMUD Posted June 28, 2007 Share Posted June 28, 2007 OK, so I know that there is an electric pump in the tank which delivers low pressure fuel to the engine. I also know that the injectors are controlled by electric and allow high pressure diesel into the cylinder at the right time. What I would like to know is, what happens in between? How is the fuel pressurised and how is it routed through the engine? Has anyone ever used bio-diesel in a Td5 or heard of someone doing it? ...and can provide links to a website giving details? I do not mean veggie oil from Tesco or old oil from round the back of the chippy but "proper" bio-diesel from a manufacturer - conforming to the BS number etc. Is there any reason why a Td5 might NOT get on with bio-diesel and what might one do to make it work better? When Td5 was new to the market, I heard a lot about how it was a crappy engine for expedition use. Not just because the ECU was bound to pack up in the middle of the first desert you went near but because of the fact that it was fussy about the quality of the fuel you used. So what makes the fuel good or bad? Is it about impurities, water in the fuel, which hole in the ground the fuel came out of, additives or what? Is there anything one can do to improve any given fuel source - by adding to or improving filtering etc.? Thanks Chris Quote Link to comment Share on other sites More sharing options...
BogMonster Posted June 28, 2007 Share Posted June 28, 2007 I can say (because we have sh*t fuel here) that it is a lot less fussy about fuel quality than the common rail engines like the Td4 which really don't get on with low quality fuel at all. The high fuel pressure is generated inside each injector which has a plunger driven off a camshaft lobe, so the fuel rail in the head is fed by the in tank pump at about 58psi and then the 25000psi or whatever it is, comes only inside the injector. The electrical part is just a solenoid that releases the pressure at the appointed time when the ECU decides it seems like a good idea. I think the problem you might have with alternative fuels is the in tank fuel pump, because that is what always packs up on them here if they have had some dodgy fuel in. If biodiesel is much thicker than normal diesel (I don't know), the pump won't like it. Quote Link to comment Share on other sites More sharing options...
Lewis Posted June 28, 2007 Share Posted June 28, 2007 OK, so I know that there is an electric pump in the tank which delivers low pressure fuel to the engine. I also know that the injectors are controlled by electric and allow high pressure diesel into the cylinder at the right time. What I would like to know is, what happens in between? How is the fuel pressurised and how is it routed through the engine? The injectors are not electric, or not in the way you think - they are operated by pushrods and rockers off the camshaft to open and close Lewis Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted June 28, 2007 Share Posted June 28, 2007 My understanding was as BM said, the injectors are pressurised internally by the camshaft/pushrods etc, the control of the amount of fuel injected is down to the solenoids. Quote Link to comment Share on other sites More sharing options...
SteveG Posted June 28, 2007 Share Posted June 28, 2007 The injectors are not electric, or not in the way you think - they are operated by pushrods and rockers off the camshaft to open and closeLewis in detail The EUI’s are located in the top of the engine inside the camshaft cover. There is one EUI per cylinder. They inject finely atomised fuel directly into the combustion chamber. Each EUI has its own electrical connection, which is linked to a common harness also located under the camshaft cover. Each of the EUI’s has its own 5 letter grading code. This code is used so that greater EUI precision is achieved. Using an injection timing map within its memory and information from the CKP sensor the ECM is able to determine precise crankshaft angle. When the ECM determines the crankshaft speed and position it closes the spill valve within the EUI. Fuel pressure rises inside the EUI to a predetermined limit of 1500 bar (22,000 lbf.in 2 ). At this limit the pintle lifts off its seat allowing the fuel to inject into the combustion chamber. The ECM de-energises the spill valve to control the quantity of fuel delivered. This causes a rapid pressure drop within the EUI which allows the EUI return spring to re-seat the pintle, ending fuel delivery. The electrical circuit that drives the EUI works in two stages depending on battery voltage. If battery voltage is between 9 and 16 volts the EUI’s will provide normal engine performance. If however battery voltage falls to between 6 and 9 volts EUI operation is restricted to a limit of 2100 rev/min. If the vehicle is fitted with a new ECM, the EUI grades for that specific vehicle must be downloaded to the new ECM using TestBook. In the event of the engine failing to rev above 3000 rev/min it is probable that the EUI grading has not been completed. Input / Output Input to the EUI takes the form of both mechanical and electrical signals. The mechanical input to the EUI is diesel fuel via the fuel pump operating at approximately 4 to 5 bar (58 to 72 lbf.in 2 ). Each of the EUI’s is operated mechanically by an overhead camshaft to enable injection pressures of up to 1500 bar (22,000 lbf.in 2 )to be achieved. The ECM controls the EUI’s to ensure that fuel delivery is precise and as intended. Cheers Steve Quote Link to comment Share on other sites More sharing options...
SteveG Posted June 28, 2007 Share Posted June 28, 2007 here's the fuel pump description Chris.. Fuel Pump The fuel pump assembly comprises a top cover which locates the electrical connector, and four fuel pipe couplings. The top cover is attached to a plastic cup shaped housing and retained on three sliding clips. Two coil springs are located between the cover and the housing and ensure that the fuel pump remains seated positively at the bottom of the tank when installed. The housing locates the two stage fuel pump and also the fuel gauge sender unit. The lower part of the housing is the swirl pot which maintains a constant level of fuel at the fuel pick-up. A coarse filter is located in the base of the housing and prevents the ingress of contaminants into the pump and the fuel system from the fuel being drawn into the pump. A fine filter is located in the intake to the low pressure stage to protect the pump from contaminants. Flexible pipes connect the couplings on the top cover to the pump. A non-return valve is located in the base of the housing. When the fuel tank is full, fuel pressure keeps the valve lifted from its seat, allowing fuel to flow into the swirl pot. As the tank level reduces, the fuel pressure in the tank reduces causing the valve to close. When the valve is closed, fuel is retained in the swirl pot, ensuring that the swirl pot remains full and maintains a constant supply to the fuel pump. The two stage pump comprises a high and low pressure stage. The low pressure stage draws fuel from the swirl pot through a filter. The low pressure stage pumps fluid at a pressure of 0.75 bar (10.9 lbf.in) and a flow of 30 litres/hour (8 US Gallons/hour) to the fuel filter. A proportion of the fuel from the low pressure stage also passes, via a restrictor, through a jet pump which keeps fuel circulating in the swirl pot. The high pressure stage draws the low pressure fuel from the fuel filter and pressurises it to a pressure of 4.0 bar (58 lbf.in). The pressurised fuel is then passed from the pump to the injectors at a flow of 180 litres/hour (47.6 US Gallons/hour). A fuel pressure regulator is located at the rear of the engine and ensures that the delivery pressure remains at 4.0 bar (58 lbf.in) by controlling the amount of fuel returning to the fuel tank. Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted June 28, 2007 Share Posted June 28, 2007 ... Not enquiring about an '07 engine then ? Mo Quote Link to comment Share on other sites More sharing options...
rick Posted June 28, 2007 Share Posted June 28, 2007 the original talk of keeping away from sus fuel stemmed from the price of new injectors. When the engine was first introduced here a number of injectors had to be replaced under warranty when less than clean outback fuel was used. The filter didn't pick it up (for whatever reason) and at the time the injectors were costing Land Rover Australia almost A$2000 each. This was from a mate of mine who was a consulting engineer to LRA at the time. (was working on a noise reduction project on that engine for military use.) Quote Link to comment Share on other sites More sharing options...
BigSi110 Posted June 29, 2007 Share Posted June 29, 2007 This may or may not help, but LRO did a feature of the Td5 engine a few months ago. Apparently, the US Army were running their Td5 Disco's on Kerosene in Iraq with no problems. I'd have thought pukka BioDiesel would be no problem at all. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted June 29, 2007 Share Posted June 29, 2007 This may or may not help, but LRO did a feature of the Td5 engine a few months ago. Apparently, the US Army were running their Td5 Disco's on Kerosene in Iraq with no problems.I'd have thought pukka BioDiesel would be no problem at all. I enquired about kero for reasons I won't go into (but it might have been something to do with green vehicles) and Land Rover said that you should not use it in Td5s under any circumstances and all warranty would be out the window. I also read somewhere that they used it in Iraq on the basis that the cost of repairs was much less than the cost/hassle of bringing in and using a different fuel in an operational theatre. Military budgets work in different ways sometimes Quote Link to comment Share on other sites More sharing options...
JST Posted June 29, 2007 Share Posted June 29, 2007 the tdi had enough problems from running purely on Kero in Iraq that i do know! Quote Link to comment Share on other sites More sharing options...
BogMonster Posted June 29, 2007 Share Posted June 29, 2007 the tdi had enough problems from running purely on Kero in Iraq that i do know! They run better on kero than on petrol tho... Quote Link to comment Share on other sites More sharing options...
rick Posted June 29, 2007 Share Posted June 29, 2007 the tdi had enough problems from running purely on Kero in Iraq that i do know! I can't see a VE style fuel pump lasting very long on kero unless you load it up with lubricant. I'd guess the internals would be blue (and seized) in a short space of time. Quote Link to comment Share on other sites More sharing options...
ciderman Posted June 29, 2007 Share Posted June 29, 2007 Chris , I recon if you filter the Scrumps out and the burnt batter first by the aid of a good stocking , The TD5 pump might be able to handle the viscosity . Quote Link to comment Share on other sites More sharing options...
GBMUD Posted June 30, 2007 Author Share Posted June 30, 2007 I have been reading a thread on AULRO where it is suggested that one guy has done 33,000km on bio in a Td5 130... so I am hopeful. There has been suggestion that the injectors may not like it much and become blocked, although this may only be in colder weather where there is a danger from waxing. Generally, there seems very little information on the physical and chemical differences between bio and dino and the reasons why bio may not work as well or may cause damage - I mean, by what mechanical/chemical means the damage might occur. Assuming that all rubber parts are synthetic rubber not natural then there should be no problem there. I understand that bio diesel lubricates better than dino diesel so wear (in pumps etc.) should not be a problem. Perhaps bio is too viscous? By the time it gets to the injectors though it should be warm - assuming a warm engine... The search/research goes on... Chris Quote Link to comment Share on other sites More sharing options...
SteveG Posted June 30, 2007 Share Posted June 30, 2007 btw, just to add, there is a fuel cooler in the last stage of the fuel feed system. Steve Quote Link to comment Share on other sites More sharing options...
Raumer Posted July 5, 2007 Share Posted July 5, 2007 I might be able to help with this question, the company I work for used to developed and made the TD5 injectors - production of final spare ones ended a month or two ago. The official line is that we do not warranty any injectors for running on more than 5% biodiesel which is why landrover won't warranty them. Research is ongoing into the use of bio fuels in our injectors (along with Bosch, Denso etc...). Obviously I cannot deviate from this line at all. Ed Delphi Development Engineer P.S. The validation of the injectors is done using kerosene to increase the wear rate - helps shorten the time for a life test along with higher pressure. If anyone needs to know the ins and outs of how they work and what they can do I might be able to help! P.P.S. If landrover had the new version (a bit bigger as it goes on 9 litre engines) then the working pressure would be 2500 bar. Another point I missed. I can't reveal what the price to Landrover was but it was an awful lot less than A$2000. I don't know how the aftermarket/replacement price is calculated but it is ridiculously high. Ed Quote Link to comment Share on other sites More sharing options...
GBMUD Posted July 5, 2007 Author Share Posted July 5, 2007 Thanks Ed. Worth knowing that the manufacturer of the injectors ruled bio out, rather than just LR not able to be bothered with the testing and so no-no'd it. I guess that you know a bit about fuel injection as well as Td5 injectors specifically. Is there any reason why and injector may not work properly with bio-diesel? What would be the properties of bio that cause problems? Cheers Chris Quote Link to comment Share on other sites More sharing options...
Raumer Posted July 5, 2007 Share Posted July 5, 2007 I know a little bit. We are doing lots of work as to how biodiesel affects our injectors. Work is being done in conjunction with Bosch etc... All of the FIE manufacturers are staying together - thats why the 5%. The whole FIE industry is running behind the times on this. When the Td5 and similar injection systems were developed biodiesel was not on the horizon and no public demand. Development for a system like this takes at least 3 years and for td5 probably more like 5 years. As I said in my first post this is the OFFICIAL line that I can't deviate from. The properties of bio diesel that may (or may not!) cause problems on FIE are - lack of lubricity, increased liklihood of holding onto water - water is very bad in Td5 type injectors, viscosity when cold (does it flow!), inconsistent fuel quality plus a few other things. Will have to check my records at work, I'm working with one of our customers on field trials with bio diesel. One big problem is that if the manufacturers warranty it for biodiesel it still needs to run exactly the same as when it's on diesel and needs to cope with the different grades available. The one big missing at the moment is a standard for biodiesel. A manufacturer warrantied bio diesel engine would have to work in all the different countries, with not even minor imperfections/changes allowed by buyers. If you are ever in the area pop by and I can explain things a bit better! HTH Ed Quote Link to comment Share on other sites More sharing options...
GBMUD Posted July 5, 2007 Author Share Posted July 5, 2007 Thanks for the details Ed. Chris Quote Link to comment Share on other sites More sharing options...
D9OSV Posted July 5, 2007 Share Posted July 5, 2007 I will keep this quick..... I have raced, owned, TD5's for six years and they are great in the UK............On normal diesel..... We raced one in Hungary in 2001 and every morning it had to be bump started, then the throttle would not do a thing until the vehicle had reached some kind of temperature, unless the vehicle was pre heated. Average temp out there -15 to -20 We started using Bio fuel in a new truck in early 2005 and could not believe the difference, i can not tell you ratios, percentages etc.........However the car drove very badly and was down on power considerably. We stopped after less than a week as we were worried about the engines longevity This year i took one to race in Northern Africa, and once i found out what the different fuel types were, and used the better quality stuff we seemed alright, unfortunatelty, and although we were using TWO air filters we completely destroyed the engine due to dust inhalation, so i can't give you the full verdict........Sorry But, i do think the TD5 is a greatly under estimated unit and deserves a lot of time and respect....... Just don't use Bio diesel Jim Quote Link to comment Share on other sites More sharing options...
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