Injector pump leak

[Greg Biofuels Forum Newbie Find all posts View Profile Close Greg]

Hi there. I know it's a long way to go in search of an answer, but nobody on my usual forum has any suggestions about this problem, so I'm hoping maybe somebody here has an idea.

I was using a veg / diesel 50:50 mix for a few months, but one day I foolishly tried 100% veg, and after a cold night the engine wouldn't start. That didn't worry me too much, and after flushing it out with diesel, it started again without a problem. What really worried me though was the fuel leak that appeared at the side of the injector pump, especially as it went away when I switched back to pure diesel. The leak seemed to be occurring at a joint between the upper and lower halves of the pump. I drive an old Pajero (1990 2.5 TDI), and even though the veg oil is very economical, it would probably cost more than the car is worth if I had to replace the pump.

After getting that fright, I haven't gone back to veg oil, but I would use it again if I could find out what happened. Any ideas?

Greg

[Gunner Donating Member Find all posts View Profile Close Gunner]

Re: Injector pump leak

Were you using unconverted Vegetable Oil or Biodiesel? The two can have different effects on engines. Prolonged use of certain types of unconverted Vegetable Oil can cause the Free Fatty Acids in the Oil to polymerise in hot parts of the engine, forming a thick, plastic-like slime that needs to be physically removed from the components, it can't be dissolved or burnt away. In a worst case, this will solidify and clog fuel lines, the injector pump and injectors as an obstruction, but should'nt cause gaskets or seals to fail. Biodiesel, on the other hand, won't solidify and clog (except in cold conditions, when it will gel like Diesel will, but that is different to polymerisation.), but it is an excellent solvent and can swell or even dissolve natural rubber seals and gaskets. A 1990 Mitsubishi MAY have natural rubber components in it's fuel system.

Diesel fuel, Biodiesel and Natural Veg Oil can all gel and solidify in cold conditions at different temperatures. If you know what type of fuel/oil you had, you could determine at what temps it will start to gel and finally solidify. Just how cold was your "Cold night"? Perhaps this is your explanation.

It is odd that your fuel leakage has healed itself. This suggests that no permanent change has taken place in the gaskets or seals in the pump, and supports the idea that it was caused by cold solidifying of the Oil, rather than chemical damage to the seals/gaskets.

Another point to consider is that the Oil/BD itself is not to blame and that this might just be normal mechanical wear and tear. How many Km's has the car done? Has the pump ever been reconditioned in that time?

[Robert Administrator Find all posts View Profile Close Robert]

Re: Injector pump leak

I have heard anecdotally that Ultra Low Sulphur Diesel can cause some seals to shrink. As Gunner mentioned, biodiesel and probably also vegetable oil can cause components made of natural rubber to swell.
What I’ve heard is that when many vehicles first used Ultra Low Sulphur Diesel, many experienced problems with leaking pumps, as the seals shrunk, causing a poor fit and the fuel leaked out. What’s the best fix for this? Biodiesel of course. Put a tank of biodiesel through the system and the seals will swell a little, thus sealing the leak.
Of course this is an imperfect solution. The best solution would be to replace the rubber seals in the pump with synthetic ones, as most modern pumps already use.
Now in your case, the swelling may have caused the leak. The inability to start is probably a separate issue caused by the higher gel point of veggie oil, as Gunner mentioned.
You could try an experiment by slowly mixing higher ratios of veggie oil/petro diesel to see if you can duplicate your leak, then back off to a lower ratio that you know is safe once you’ve found the leak point. A better idea would be to look for a cheap gasket kit for your pump that uses synthetic seals, or find a mechanic that can do this.
You could also try using biodiesel rather than straight vegetable oil blended with petro diesel. You might get better results from this.

[Greg Biofuels Forum Newbie Find all posts View Profile Close Greg]

Re: Injector pump leak

Guys, I thank you for replying so promptly.

The whole biodiesel thing is very new here (and in Britain). It isn't a developed industry at all, and even though our government has started to provide some sort of support, it's all rather half-assed. Therefore, most people using any sort of bio-fuel tend to be oddballs like myself, just trying things out to see how it goes. I know a few people using a 50:50 mix of veg-oil and diesel for a year or two without apparent difficulty, but it seems every car is different.

@Gunner. I was using unconverted vegetable oil, and I would be very worried at the thought of creating polymeric compounds in my injectors (or any other part of the engine). I didn't realise this could happen, but I'm new to it all and have a lot to learn. It's particularly worrying, as a number of companies, both here and in mainland Europe, sell conversion kits to run vehicles on straight veg oil, usually employing some form of heating to reduce the viscosity, and also normally having dual veg and diesel tanks, for starting and stopping. But if the stuff is going to turn into plastic inside the engine, then this approach is clearly very hazardous. Do you know how high the risk is of this happening?

The night I had the problem wasn't especially cold: it was just a little chillier than usual. Maybe minus 1 or 2 at worst. To answer your question about the car, it's done 260,000 km, and I bought it as a Japanese import with 155,00km on it. I've never had the pump serviced, but I don't know about the previous owner. I would guess not. However, the leak definitely went away, and has not come back, which seems strange, as I would have thought if anything the thinner diesel would be more likely to leak. That's what I find hard to understand.

@Robert. I'll look at the possibility of fitting synthetic seals. I have been told that on this particular pump, there isn't a gasket, just two machined faces, but that could be wrong. There aren't too many people specialising in injector pumps, and they tend not to be very forthcoming with information. I suppose it's hard to blame them. I was actually going to do what you suggested, by experimenting with fuel ratios, but I'd like to understand more about this leak first. Also, now that I've read Gunner's comments, I'm even more reluctant to take a risk with my old but reliable machine.

Thanks again for the advice

Greg

[Gunner Donating Member Find all posts View Profile Close Gunner]

Re: Injector pump leak

Greg, don't be put off trying alternative fuels, just try to find the answers that eliminate the risk.

While neither denying or validating thier opinion, have a read of this page and also this one. I say that, as some in the Biodiesel world have found "Issues of Disagreement" with the writer of that site and I'm not in a position to say if they are issues of technical merit, or just politics.

An ambient temp just under freezing would indeed cause SOME types of vegetable oil to solidify. Unfortunately, many brands of oil don't specify the content, just proclaiming "Blended Edible Vegetable Oil" (perhaps food labelling laws in Ireland are more specific). If that is the case, take a sample and put it in the refrigerator of freezer with a thermometer and monitor it to see at what temp it starts to go cloudy and finally solidify.

Sláinte!

[bouncyman Biofuels Forum Newbie Find all posts View Profile Close bouncyman]

Re: Injector pump leak

hi this is my first post on this wonderfull forum and i would just like to add that i have had this problem myself infact its a normal problem in the uk.

the fix for this is to change the top seal which is redilly available here. if i can help any further please contact me.

[Greg Biofuels Forum Newbie Find all posts View Profile Close Greg]

Re: Injector pump leak

the fix for this is to change the top seal

That's great information. I'm relieved to discover that there's nothing unusual about what happened, and no serious damage has been caused. Unfortunately, however, I'm not very knowledgeable about injector pumps (well, the truth is I know nothing at all about them!). So what exactly did happen, and why will a new seal fix the problem? Is this a big job? Can it be done with the pump in situ, or does it have to be removed? Sorry about all the questions, but I think it's important to understand why this happened, and hopefully, maybe other people will learn something helpful as well.

[darren leonadas Senior Member Find all posts View Profile Close darren leonadas]

Re: Injector pump leak

Hi Greg, You're a brave man doing a 50/50 diesel SVO, and even braver to go 100% SVO.
Re SVO . It is crucial that you start your car on Diesel (fossil or Bio) before you switch over to SVO, I May be telling you something you already know, but this means having a seperate fuel tank, be it only very small, to start and to switch off the car. So that you always start a cold car on diesel then switch over as the car gets hot. The most ingenious solution i have heard of is to use/convert over, the water washer tank that would normally wash the windscreen and do away washing your windscreen. no big loss. then a simple solanoid switch kicks it over to the main fuel tank.
SVO changes in VISCOCITY as it gets hot . You may observe this when you put it into a very hot frypan and swish the frypan around. Very hot SVO has a viscocity similar to diesel, but cold SVO has a much thicker/heavier viscosity. The more the SVO is heated, then cooled, in the case of WVO which has had the **** cooked out of it, the more resistance the SVO has to losing its viscocity.
So if you start a cold engine on SVO (I'm amazed it even started) the injectors cant cope with the much heavier viscocity and something has to give and either you blow a seal or worse seriously damage your injectors.
So Now when you switch back to SVO that seal is leaking.
So the moral to the story is only pump SVO into a hot injector.
RE 50/50 VO and diesel, it again is an issue of finding a similar viscocity to that of diesel. Mixing it (diesel) 50/50 adds to the viscocity of the new fuel. So to get a desired viscocity- The 50/50 fuel mix should be (if you insist on mixing a fossil fuel with veg oil) VO and Kerosine.
I Hope i have provided some info for you that you didnt already know.
Happy dieseling , Darren.

[stephen Biofuels Forum Newbie Find all posts View Profile Close stephen]

Re: Injector pump leak

Hi, first time on the forum
Can't comment on the SVO affecting the injector pump, however with Older Mitsi's and Toyota's with Rotary(VE) type pumps any change from normal high sulphur petrodiesel can cause the seals to leak. The aromatics in high sulphur fuel keep older seals swollen when they would normally start to leak.
I'd say the solution is not a quick one, re-sealing a injection pump is not a backyard job. Does'nt sound like it's the SVO though, probably more the age and state of the pump.

[hdj80 Senior Member Find all posts View Profile Close hdj80]

Re: Injector pump leak

I had to replace the seals in my 91 HDJ80 due to ULSD. Didn't drip fuel it Dumped fuel.
It is a Direct Injected 4.2litre 6 cylinder Turbo Engine.
Cost $AU2300 that included full pump rebuild and new injecters.
New seals need to be vitron as pre 93 were rubber and both ULSD and Biodiesel will eventually distroy them. This includes rubber fuel lines, however these should last longer, but still need to be checked often.

[DIY Biofuels Forum Newbie Find all posts View Profile Close DIY]

Re: Injector pump leak

Hello Guys,

Can't run on 100% SVO ?? Please don't tell my car

I have a Peueot 206 1.9D from 1999.
The original injection pump was a LUCAS/CAV (crap if you want to run SVO), so I got a second hand from a scrapyard (app USD120)
Installed a Elsbett kit.

Was running on 100% Pure rapeseed oil (cold pressed and 3my filtered) all summer & spring.

Here in the winther I'm adding 5-10% diesel to make the start'n'run smoother - but I have been running at -5 degrees celsius with 100% SVO

At lot of it all comes down to the injector pumpe.
Some will work really good with SVO
Some will work
Some won't

About the 1 or 2 tank system. This very much depends on the engine.
As a thumb-rule : old cars can do with 1 tank 100% SVO, newer cars needs 2 tank 100% Diesel / 100% SVO.

On www.elsbett.com you can find a list of many cars - also showing weither Elsbett sells 1 or 2 tank solution (this is ofcourse no a 100% can/can't do - but is't pretty close )

Greetings
DIY
Denmark

[dieseltoy Biofuels Forum Newbie Find all posts View Profile Close dieseltoy]

Re: Injector pump leak

I have a 1992 2LT motor, and my pump is starting to leak after using b99/b100. Does onyone have a part # of the upper seal for the newer Viton version?

Here in The US, only 82~87 Toyota diesels are listed in dealer databases.

It looks like the upper seal is leaking, but I haven't pulled it apart yet. If anyone has any experience with this, please let me know if there are other seals I should be concerned about also.

I appreciate any help.

Thanks!

[Terry Syd Senior Member Find all posts View Profile Close Terry Syd]

Re: Injector pump leak

Dieseltoy, are you referring to the upper lid gasket. I understand that is one that will eventually start to leak.

I had to change the fuel shut-off valve on my injector pump and while I did that I changed the top lid gasket and the throttle shaft 'O' ring as a precaution. The gasket kit was A$33. It is a standard kit that works for heaps of models of injector pumps. The new lid gasket has a series of 'teeth' that keep the gasket vertical in the groove. The old style gasket would tend to crumple over.

I think I wrote a bit about that on the Surf forum, I'll see if I can find it.

Yep, here it is. The last post are the instructions of how to do the job. Once you've done one you can do the job in 10 minutes (with the pump off the vehicle) - this first time took me 2 hours of careful attention to detail to make sure I didn't damage the pump.

You can do the job with the pump on the vehicle, you just have to remove a bunch of things and take out the fuel adjustment screw in the back of the pump. Take close attention to the number of turns the screw uses to come out. Even then you may have to tweak it a bit to get the mixture right.

http://www.toyotasurf.asn.au/forum/v...331&highlight=

[Mark P Biofuels Forum Newbie Find all posts View Profile Close Mark P]

Re: Injector pump leak

Hi there. I know it's a long way to go in search of an answer, but nobody on my usual forum has any suggestions about this problem, so I'm hoping maybe somebody here has an idea.

I was using a veg / diesel 50:50 mix for a few months, but one day I foolishly tried 100% veg, and after a cold night the engine wouldn't start. That didn't worry me too much, and after flushing it out with diesel, it started again without a problem. What really worried me though was the fuel leak that appeared at the side of the injector pump, especially as it went away when I switched back to pure diesel. The leak seemed to be occurring at a joint between the upper and lower halves of the pump. I drive an old Pajero (1990 2.5 TDI), and even though the veg oil is very economical, it would probably cost more than the car is worth if I had to replace the pump.

After getting that fright, I haven't gone back to veg oil, but I would use it again if I could find out what happened. Any ideas?

Greg

Hello, I am a newbie and have a question for Greg as I have expereinced exactly the same problem and wish to know how to flush my system? I have a J reg 2.5 TD Paj and foolishly tried 100% svo and had a cold night the other night and it would not start, since then I have tried starting and run the batteries down twice. I then came across your blog and thought maybe all is not lost. If you could advise me on how to flush my system to get my Paj running again It would be very appreciated and will not be running 100% again until summer! Many thanks in advance for any help given. Regards, Mark P

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Injector pump leak

Mark,
You will need to remove the vegetable oil from your fuel tank, fuel lines and filter. If it is still liquid that should be fairly easy. If the veggie oil has solidified, you will need to heat the fuel system to remove the oil. You may wish to move the vehicle, so get a can of fuel to feed the engine while you shift the car. Follow the steps after rmoving the veggie oil from the tank, lines and filter, below.
Once you have removed the veggie oil from the tank, lines and filter, add diesel to the fuel tank and re-prime the injector pump, until diesel flows from the bleed valve.
I recommend getting a good supply of hot water (preferably boiling water) and trickling the water over the injector pump, injectors, fuel filter and fuel lines before trying to start the engine. A block heater may provide a similar effect if used for a few hours.
Allow the GPs to glow a couple of times (watch the interior light to see when the GPs turn off - it will brighten perceptably) and then crank the engine.
If it fires, but cannot get going, remove the air cleaner cover and have someone spray some WD40 (aerosol lubricant, NOT ether starting aid - ether will cause damage!) into the intake while you crank. The engine will start on the WD40 and you should have some throttle response if the IP is working. Have the person spraying the WD40 stop spraying when you have throttle control. do not allow the engine to drop to idle until you are confident that it will not stall.

If you have a CAV IP, this will probably not work as they fail when using cold veggie oil, even in a blend. Heck, they even fail on 100% diesel!