Biodiesel

Discuss (and cuss) the Nissan LD-series OHC Six diesel engine, popularly available in the US in 1981-83 Datsun/Nissan Maxima Sedans & Wagons.

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goglio704
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Biodiesel

#1

Post by goglio704 » 14 years ago

Who is running biodiesel in their LD28? What percentage? Results good, bad, or ugly? Bio is becoming commercially available in my area - mostly the 20 percent blend. I've heard higher concentrations can be bad for rubber parts - hoses especially. I know it tends to disolve fuel sytem crud and send it to the fuel filter.
Matt B.

83 Maxima Sedan, LD28, 5 speed, white, 130k miles. My original Maxima.
83 Maxima Sedan converted from gasser, LD28, 5 speed, 2 tone blue, 230k miles
82 Maxima Sedan, LD28, 3 speed auto, 2 tone Gray/Silver, 140k miles
81 810 Sedan, LD28, 3 speed auto, rust, rust, and more rust!

2005 Jeep Liberty CRD

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asavage
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#2

Post by asavage » 14 years ago

I am active in our local BD community. In fact, the privately run BD outlet here is going co-op next month, and I've been attending the planning meetings. So I'm hot on biodiesel. I sell people on it all the time, used to hand out flyers at work, I maintain our fuelling station (in part), and I stock an anti-gel kiosk there (PowerService Arctic Express Biodiesel Antigel).

I have bought and sold two '82 Datsun 720 diesel pickups in the last two years. See my story on converting the first one to viton fuel lines right here on this site, in the SD2x forum. Pictures and everything.

If you run B100 in a Datsun, you WILL have to replace the fuel lines. On that '82 720, it took about eleven months to spring a leak, from straight petrodiesel to B100.

I have run three tankfulls of B100 though my '82 Maxima, but it's taken me two years to do it (I don't drive the Maxima much), so I can't say much about the mileage, driveability, etc. in the Maxima.

However . . . my IP leaks. And it started leaking after about two tanks of B100. And I don't think that's a coincidence, because New Zealand Ministry of Economic Development's report on problems with VE IPs says that others with VE pumps are having trouble with ULSD over there, and the same low-volatility that ULSD has is found with BD. Please read at least part of this thread in the biodieselnow.com support forum.

I think the low volatility issue is real, and I think that whether one runs BD or not, it'll affect all VE IP owners next September, 2006, when the entire US goes to ULSD by Fed mandate. Don't get me wrong, I've very hyped about the US finally getting the clean fuel it desperately needs -- reduction of sulfur levels from the current >300ppm to <15ppm means that NOx catalytic converter technology that already exists can be appliied across the board to all diesels in America, and we can finally get >100k mile emissions warranty compliance, which is the only real reason why we can't buy diesel vehicles in quantity in the US (the mfgrs can't get 100k mile NOx compliance with our dirty fuel).

But our older VE pumps are (I predict) going to all have to be resealed. At this point, I'm assuming that this is going to entail possibly only the shaft seal replacement (and make certain the replacement seal is BROWN, not black! Brown is viton, black is nitrile/buna-n). If that's the case, the next step is to determine if the seal can be replaced without IP removal. It's possible that it is. It may be that replacing the shaft seal is only a little more work than replacing the IP belt, but at this point I do not know. If the IP has to be removed to replace the shaft seal, then the labor involved is quite a bit more, and of course we'll have to re-time the IP.

Do you see why I'm so interested in finding alternative methods to checking the IP timing?

Steve & I have found several parts sources for the shaft seal, contained within a "seal kit" that includes other stuff, some of which could only be replaced with a lot of work.

Personally, I'm only interested in running B100 for the majority of my diesel driving, for a handful of reasons that don't have anything to do with the LD28. For that reason, I will be on this issue like files on shit (as they say). It burns a lot cleaner than petrodiesel, and your oil will stay cleaner too (but still change it on time, unless you run a real synthetic -- by this I do not imply Syntec, or Valvoline synth, or Pennzoil synth, or any other Group III-based "synthetic" oil, but a true synthetic such as Royal Purple, Redline, Mobil 1, or AMSOil).

If anyone starts on an IP reseal project before I get to mine, I definitely want to be kept abreast. And pictures! We want pictures!

I guess I should mention that I bought up the last two NOS (brand new) known 1982 IPs in the US two years ago -- they're still new-in-the-Nissan-box. Paid less than the cost to rebuild one . . . and, no, they're not for sale.

BTW, OEM-Surplus.com still has a lot of LD28 and Gen1 Maxima stuff for sale. They're the ones who sold me the new IPs, and they still have a brand-new CSD (Cold Start Device), and last time I looked they had brand-new seat upholstery and door panels. You can make them an offer, and I can tell you that they'll sometimes take them. Definitely worth a look.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

goglio704
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#3

Post by goglio704 » 14 years ago

Thanks for the info. Here are some more questions:

1. With this next change in petrordiesel will we be running the same diesel they use in Europe?

2. Does Bosch have a fix for the problems with these pumps? I know Stanadyne had some updates for their pumps when low sulfer fuel came out a few years ago.

3. In general are these pumps rebuildable and supported by Bosch?

4. I realize all bets are off now, but what was the life expectancy of these pumps before diesel started changing. 100k 200k?

5. What I'm really wondering is if Bosch has updates for these pumps and their life expectancy is up anyway, I might as well get them rebuilt and updated. Not a cheap proposition in the short term, but maybe better in the long run.

6. I thought the issue with low sulfer diesel was that the sulfer removal process screwed up the lubricating properties of diesel, but it sounds like there are also issues with the fuel chemically attacking rubber?

7. I thought bio was supposed have better lubricating properties than low sulfer diesel?
Matt B.

83 Maxima Sedan, LD28, 5 speed, white, 130k miles. My original Maxima.
83 Maxima Sedan converted from gasser, LD28, 5 speed, 2 tone blue, 230k miles
82 Maxima Sedan, LD28, 3 speed auto, 2 tone Gray/Silver, 140k miles
81 810 Sedan, LD28, 3 speed auto, rust, rust, and more rust!

2005 Jeep Liberty CRD

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asavage
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#4

Post by asavage » 14 years ago

goglio704 wrote:1. With this next change in petrordiesel will we be running the same diesel they use in Europe?
I think so, but I admit that I am not sure. You'd have to compare 15ppm sulphur.
2. Does Bosch have a fix for the problems with these pumps? I know Stanadyne had some updates for their pumps when low sulfer fuel came out a few years ago.
Again, I'm not certain, but there's at least one reference in that thread I linked above (biodieselnow.com forums) that a shop mentions the replacement shaft seal being brown. That's a clear indication in my mind that it's viton. However, I've seen a black seal in a kit too, which may be old stock. I'm wary of the parts stream being purged of non-ULSD-compatible stuff.
3. In general are these pumps rebuildable and supported by Bosch?


Yes. Millions on and off the road worldwide. Lots in industrial and ag equipment. Unfortunately, rebuilding them isn't cheap. Resealing them should be, though. I had a guy in the shop yesterday who owns a couple of diesel Rabbits (pre-Golf VW diesel) and he mentioned an outfit in northern California that's selling some new version of the old VE 4-cyl. IP for under $700 now. I will want to track down that one.
4. I realize all bets are off now, but what was the life expectancy of these pumps before diesel started changing. 100k 200k?
I'm thinking in the 150-200k range in typical (American, unmaintained) trim. The Stanadyne DB2 IPs in early Ford 6.9l diesels (I own one too) are failure prone after 150k. I had no trouble with my DB2 in my '83 GM G30, but it got rebuilt at 145k due to fuelling with unleaded -- no self-serve in Oregon, and the attendant didn't see the "Diesel Fuel Only" sticker on the fuel door, filled it up with 31 gallons of unleaded. I made it eight miles before it stalled. Walked eight miles back, too. Their insurance company paid to have the entire fuel system purged and rebuilt: new injectors, IP, lift pump, filters. $2300 (done at a Chevy dealer). Never idled smoothly after that rebuild, even though I brought it back to them several times. After I found that the dealer's wrench was leaving parts off, I stopped taking it there altogether and counted myself lucky that it ran as well as it did. Chevy dealers hate working on vans, and the diesel was never popular with them either.
5. What I'm really wondering is if Bosch has updates for these pumps and their life expectancy is up anyway, I might as well get them rebuilt and updated. Not a cheap proposition in the short term, but maybe better in the long run.
I can't fairly advise you on this one. The cars aren't worth a whole lot except to us. For that reason, I suspect that not a lot of LD28 IPs are getting rebuilt, and that means that the rebuilders are losing their experience with them. IOW, you might get ripped off. I have terrible luck with having my equipment serviced by others.
6. I thought the issue with low sulfer diesel was that the sulfer removal process screwed up the lubricating properties of diesel, but it sounds like there are also issues with the fuel chemically attacking rubber?
You've got both of those exactly right. The severe hydrotreating process that is instrumental in cleaning up the sulphur from diesel also reduces the lubricity of the fuel -- it's important to point out that it's not the sulphur itself that has the lubricating properites.

The sealing issue is reputed to be a problem like this (some conjecture here, not all mine): because the current PD has aromatics that act as seal swell agents (a tribology term, for those of you conversant with the differences and history of mineral oils and synthetic oils). Seals that have been subjected to seal swell agents for a number of miles have . . . swollen. And decreased their operating clearance to proximate parts. On moving parts with seals, those seals have "worn in" for the tighter clearance.

Now remove the seal swell agents in the fuel. The seals harden and to some extent shrink -- this is normal. Clearnances open up, leaks occur. It isn't so much a problem with BD "attacking" the seals as it is a byproduct of removing the chemicals that were keeping the seals supple and tight.

It could be, and has been conjectured, that if you reseal a VE IP and then run primarily BD in it, even with out "updated" seals, it might be OK. I just don't know, and that's clearly guesswork.

In the case of very old sealing parts, comprised of nitrile (buna-n), BD does actually act as a seal swell agent, but way overboard, and the seals will literally fall apart. I haven't heard of this happening in an IP, but the fuel lines were mush on that' '82 720 SD22 this summer, after a year of BD. We were expecting that, however, and I'd already ordered the viton lines for it.
7. I thought bio was supposed have better lubricating properties than low sulfer diesel?
It does. Hugely so. ULSD itself doesn't lube as well as high-sulphur diesel (for reasons mentioned above). Back in '90, when we moved to the current "low sulphur" diesel of no greater than 500ppm (on road only), refiners got lots of complaints of IP and injector failure, and they quickly responded by adding additives that boosted the lubricity of the "low sulphur" diesel. That's where we are now. Adding BD vastly (hugely) improves the lubricity, but still does not contain the seal swell agents that our VE IPs need (apparently: this is still conjecture).

Since I just posted tonight on BD lubricity in another forum, I'll copy that info here -- admittedly, not well researched, I just grabbed a few relevant things and threw them together:

http://www.biodiesel.org/markets/pre/default.asp

"Lubricity data indicates that 2% blends of biodiesel offer the highest amount of lubricity benefit for the least incremental cost. Testing has shown that 2% blends of biodiesel can provide any type of distillate fuel with sufficient lubricity."

US Army TARDEC Fuels & Lubricants Research Facility report, "Evaluation of Biodiesel Samples as Fuel-Lubricity Enhancers"

Look at the table on Pg 10 (2), under Scuffing Load Wear Test, for example.

Pg 18 (10), "Most biodiesel samples improved JP-8 fuel lubricity to passing when added at 0.5% vol" (JP-8 is a jet fuel, roughly equivalent to kerosene I'm told)

Many references (Lucas & Stanadyne among them at the bottom) of this PDF. I didn't chase them all down.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

Dr. Jones
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Location: Raleigh NC

biodiesel

#5

Post by Dr. Jones » 14 years ago

I am thinking of converting mine. But don't know what needs to be replaced. Are there other seals besides the front? What is the difference between B-100 and SVO? Sorry, but I'm pretty sure that we would have to the pump off to change this seal I only say this cause I pulled the pump drive gear off when timing my automatic. Also if anyone knew of some well designed processors and/or heater setups for SVO that would be greatly appreciated. Thanks, Joe
'82 Maxima Sedan x2
'92 Saab 9000 Griffin Edition Wrecked
'80 Ford E100(twisted tranny) SCRAPPED

Carimbo
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#6

Post by Carimbo » 14 years ago

SVO=Straight Vegetable Oil. Peanut, canola, soy, etc., the oils commonly used for cooking, frying food. Generally much higher viscosity than petro diesel. Most diesel engines could successfully burn it if you could get it to flow thru the fuel lines/filters/IP/injectors without clogging. Heat is the common method used to reduce the SVO viscosity to a level the IP can accept and that can be properly atomized by the injectors. 150-180*F at the IP inlet is a commonly accepted temp.

Boidiesel is a result of chemically converting the SVO to remove its glycerin content to reduce its viscosity so it is similar to petro diesel so the IP and injectors can handle it without breaking. However BioD does start to gel at a higher temp than petro diesel so cannot be used straight in some climates.
BioD has more solvent action than petroD and can attack rubber hoses/seals.

Both have much higher lubricity than petroD.
Both are much less biohazard than petroD (although processing BioD does use hazardous materials).
Both are commonly made from WVO (Waste Vegetable Oil) gathered from restaurants.

I am currently experimenting w/ burning WVO in my '82 Maxima. My opinion is that the LD28, being an indirect injection (said to be easier to run WVO) with minimal electronics, should be a great specimen but the IP and some of its features do not lend themselves to easily run WVO.

It HAS been done before. One early pioneer Author, From the Fryer to the Fuel Tank transplanted a WVO-burning turbocharged LD28 into a Z-car. Don't know the details.

Carimbo
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#7

Post by Carimbo » 14 years ago

Oops, sorry, I see you asked about B-100, not biodiesel in general. B-100 denotes the percentage of biodiesel to petrodiesel. In this case, 100% biodiesel. B-20 is 20% boidiesel/80% petrodiesel for example.

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asavage
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#8

Post by asavage » 14 years ago

I'm visiting my father in SoCal right now, don't have a lot of time, but I'll see what I can do.
Carimbo wrote:SVO=Straight Vegetable Oil. Peanut, canola, soy, etc., the oils commonly used for cooking, frying food. Generally much higher viscosity than petro diesel. Most diesel engines could successfully burn it if you could get it to flow thru the fuel lines/filters/IP/injectors without clogging. Heat is the common method used to reduce the SVO viscosity to a level the IP can accept and that can be properly atomized by the injectors. 150-180*F at the IP inlet is a commonly accepted temp.
I agree with much of what you've said, I'll just add a couple of things.

The inline IPs (old MB, SDxx Nissans, etc.) work better with untransesterified fuels than the rotary/distributor type IPs (Stanadyne DB2/GM 6.xl, IH/Ford 6.9l/7.3l, Nissan LD28, VW). The inline IPs are more tolerant of fuels whose viscosity change as much as SVO/WVO does.
Boidiesel is a result of chemically converting the SVO to remove its glycerin content to reduce its viscosity so it is similar to petro diesel so the IP and injectors can handle it without breaking. However BioD does start to gel at a higher temp than petro diesel so cannot be used straight in some climates.
Hmmm. One issue with untransesterified oil is the acid content. If you *leave* fuel in the IP, lift pump, or injectors, the fuel can etch the metal bits. One more reason to make damn sure you purge the IP and injectors with BD or PD before shutdown. That, and starting up with cold SVO in a DB2 can actually snap the input shaft due to the torque requirement of trying to pump cold WVO. It's happened.

Even thinned oil will not produce a correct spray pattern, which leads to coking (deposits formation) which negatively impacts the spray pattern more, leading to more coking, etc. until the rings begin sticking and compression drops and now you can't start the engine in cold weather etc. Increased lube oil contamination due to increased blowby.
BioD has more solvent action than petroD and can attack rubber hoses/seals.
This is a bit misleading . . . BD will soften nitrile (Buna-N) and real rubber (hardly ever used in automotive apps), and fuel lines on older vehicles are usually comprised of nitrile, so replacement of the fuel lines is definitely necessary -- see my my viton lines replacement post in the SD2x section for more info.
Both have much higher lubricity than petroD.
Are you sure that WVO has higher lubricity than PD? I can cite references about BD's lubricity, but not for WVO.
Both are much less biohazard than petroD (although processing BioD does use hazardous materials).
Agreed. The flash point of BD is substantially higher than PD. It's not even a hazardous material (unless you step in it and slip & fall). And its cetane rating is higher than pretty much all PD available in the US.
It HAS been done before. One early pioneer Author, From the Fryer to the Fuel Tank transplanted a WVO-burning turbocharged LD28 into a Z-car. Don't know the details.
That car was recently sold on eBay (in the last six months). Joshua Tickell was the force behind it. The car was not in great shape at the time of sale, but the LD28 transplant to a 280Z is practically a bolt-in.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

Carimbo
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#9

Post by Carimbo » 14 years ago

Quote: Both have much higher lubricity than petroD.

Are you sure that WVO has higher lubricity than PD? I can cite references about BD's lubricity, but not for WVO.
I knew this would get me in trouble! Esp. because WVO is so slippery (pun intended) to precisely define. Too many variable factors: Orig. oil makeup, extent to which it was filtered/dewatered, age, temps it was subjected to, etc.

If one can presume the orig. oil is soy, and the cooking/frying/filtering/dewatering processes have not destroyed its inherent properties, then we can infer from the following report Evaluation of the Lubricity of Soybean Oil-based Additives in Diesel Fuel
which finds soybean oil an effective lubricity additive to petroD.

Don't know if that is proper evidence that can survive rigorous scientific scrutiny.

Anyway, possibly a larger problem than WVO's inherent lubricity (or lack of) is free fatty acid (FFA) induced buildup on steel internal IP parts that interferes with the IP's internal lubrication system (see how they scrape the buildup off the rotor w/ a knife!) f23.parsimony.net/forum49387/messages/126321.htm
Is that part of the feed pump?

PS: Did I get the quote of the quote properly pasted?

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asavage
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#10

Post by asavage » 14 years ago

Anyway, possibly a larger problem than WVO's inherent lubricity (or lack of) is free fatty acid (FFA) induced buildup on steel internal IP parts that interferes with the IP's internal lubrication system (see how they scrape the buildup off the rotor w/ a knife!) f23.parsimony.net/forum49387/messages/126321.htm
Is that part of the feed pump?
Yow! That IP is trash!
I can't read German, and didn't try to run it through Babelfish, but that looks like more than just bad fuel, it appears that corrosion has occurred as well.

Yes, that's the internal vane pump, which also functions as a lift pump on the VE. I've read the Bosch VE IP manual cover-to-cover twice now (it takes that, to understand the translated German), and now I recognize the pieces.

If the vane pump loses much efficiency, the IP timing won't advance, because it's hydraullically controlled. If the vane pump output pressure drops, the timing piston won't move correctly, and the effect is retarded timing.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

Carimbo
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#11

Post by Carimbo » 14 years ago

But our older VE pumps are (I predict) going to all have to be resealed. At this point, I'm assuming that this is going to entail possibly only the shaft seal replacement (and make certain the replacement seal is BROWN, not black! Brown is viton, black is nitrile/buna-n). If that's the case, the next step is to determine if the seal can be replaced without IP removal. It's possible that it is. It may be that replacing the shaft seal is only a little more work than replacing the IP belt, but at this point I do not know. If the IP has to be removed to replace the shaft seal, then the labor involved is quite a bit more, and of course we'll have to re-time the IP.
Al, is the VW (older) Bosch VE IP similar enough to the one on the LD28 to warrant trying this method? He modified a small gear puller with jaws made out of ground down 4mm allen wrenches.

At least maybe it gives you more ideas.

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asavage
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#12

Post by asavage » 14 years ago

That's a very good link, Thanks! The best part is that he provides a link to the replacement seal! This is great news.

The tool he fabricated is possibly more elaborate than what I'll try. I will want to attempt the "sheet metal screw plus slide hammer" method. I also want Steve to ship me an IP for my education (hint, hint).

Thanks again for finding and posting that link!
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

oldmax82
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#13

Post by oldmax82 » 14 years ago

Matt:

I have been running biodiesel in my 82 wagon for about a year. During the summer I ran B100 and have not had a problem with the IP although the information supplied by Al and the info coming from New Zealand are causing me some concern.

This winter I have been using B80. I make biodiesel in my garage from waste vegetable oil. It has a cloud point of about 36-38 degrees F and I like to mix in some petro diesel. Subjectively, I think it runs better on B80 than B100.

Terry
82 Maxima diesel wagon

Dr. Jones
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#14

Post by Dr. Jones » 14 years ago

As far as the IP goes all we need to do is replace the front seal and will this make our stlye pump be as relible as with PD? Does any one know where I can get a 110 lower heating element for a water heater?

Joe
'82 Maxima Sedan x2
'92 Saab 9000 Griffin Edition Wrecked
'80 Ford E100(twisted tranny) SCRAPPED

TheDieseliminator
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#15

Post by TheDieseliminator » 14 years ago

I'm wondering can we buy seals for the LD28 injection pump that will prevent it from leaking once we start running the ultra low sulfur diesel fuel that the U.S. will be receiving pretty soon? All my dad and I drive are 80's diesel vehicles and I'm wondering if we'll have to change the seals on all the injection pumps in all our vehicles to accomodate this new diesel fuel that supposedly doesn't lubricate as well as our current diesel fuel that we use in the U.S. I'm not too experienced on this subject and am just trying to learn more. I know others will have a good amount of opinions and true facts to discuss too.

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