cdw904

Just want to share>

Figure 1:
Here is the OEM fuel system schematic for my 1995 Mercedes E300 Diesel.

1) From Diesel Tank to Heat Exchanger
Rubber from tank to steel line. The steel line runs all the way to the engine compartment where it then changes back to rubber (under the windshield washer tank). From there it goes to the heat exchanger in the head.

2) From Heat Exchanger to the Pre-filter
Leaves the heat exchanger via a "quick disconnect" and a hard plastic fuel line. This goes to another disconnect on the filter assembly. The filter casting holds the pre-filter which is a screen strainer or Pre-filter.

3) From the prefilter to the lift pump
Leaves the prefilter via a disconnect and a hard plastic fuel line. This goes to another disconnect on the lift pump. The lift pump is a low pressure mechanical fuel pump which assists or "lifts" fuel.

4) From the lift pump to the filter
Leaves the lift pump via a disconnect and a hard plastic fuel line. This goes to another disconnect on the filter. This forces fuel INTO the filter.

5) From the Filter to the Injector pump
Leaves the filter via a disconnect and a hard plastic fuel line. This goes to another disconnect on the Injector pump.

6) From the injector pump to the:

A. injectorsLeaves the inj. pump via 6 steel lines that go to6 respective injectors. These are high pressure lines.

B. filterLeaves the inj. pump via a banjo bolt disconnectand a hard plastic fuel line. This goes to anotherdisconnect on the filter. This connection is ajunction point for all return lines.

7) From the injectors to the filter:
Unused fuel leaves the injectors via small braided rubber return lines and goes to a disconnect on the filter. This connection is a junction point for all return lines.

8) From the return line junction on the filter to the Fuel Tank
Fuel is allowed to go 2 direction; back into the filter, or back to the fuel tank.

Rubber from filter to steel line. (changes under the windshield washer tank) The steel line runs all the way to the rear of the vehicle where it then changes back to rubber. From there it goes back into the tank.










Figure 2:
Here is the remodeled fuel system to allow for future use of biodiesel.

Differences from figure one:
1) Filter and lift pump have swapped locations
Filtered Biodiesel will be fed directly to the pump. The original configuration would route biodiesel through the OEM filter which is not wanted.

This will also Pull fuel thru the filter instead of Push it thru like before.


2) Return line has been removed and capped on each side.
This will not allow biodiesel to be fed back into the OEM diesel filter. See figure 3 for further explanation.

3) All rubber has been changed.
All o-rings have been changed to Viton. See Mercedes E300 Diesel Fuel Leak (OM606) 1995 - Laterfor o-ring replacement.

Hoses have been changed to SAE J30R9 (get this at Autozone, Napa, etc. It has a blue inner lining) which will hold up to biodiesel. I carefully cut the hard plastic lines off the fittings and installed 5/16 ID SAE J30R9 fuel injection line. I used srcew drive hose clamps to hold the hose on the fittings.

Piedmont Biofuels » Solvency Effects

The plastic fuel line would probably hold up to the biodiesel, but "re-wiring" the fuel circuit changed fuel line lengths. I also need to add in two selector valves. The plastic is too brittle to do that.

4) Return lines were changed to Viton
I used 6 ft. of P/N 5119K791 to replace the aged, leaky braided return lines. Kind or expensive at $3+ per ft., but chances are, I will never replace them again. Also, the braided OEM stuff WILL NOT hold up to biodiesel! Viton will.





The car runs great with no fuel leaks! Even reconfiguring the fuel circuit has had no effect.





Figure 3:
Here are my future plans to complete the biodiesel system.

1) All items in green will need to be added (See Fig 3). Hopefully the picture describes why the fuel system remodel was needed. The Viton and new fuel lines should prevent and deterioration. I am leaning toward glow plug fuel line heaters directly before the filter and directly before the lift pump. I live in TX so heat isn't usually a problem

myfirstbenz

Are you running B100 or veg oil? I would see no need for a separate tank if you have B100 or a mix there of. Only Veg oil needs a separate tank and heating system.

Bigpete123

Good for you, man. Now to get the rest of America on board with alternative fuels...

I'm actually inverviewing with a local biodiesel startup company and I'm hoping for stock options. I'm willing to bet this industry will really pick up over the next 10 years.

cdw904

I am going to run WVO in my car... "Biodiesel" was not the correct term to use. Sorry.

myfirstbenz

You lucky sob. I wish I had a diesel, but the 300TD's were about 2-3 times the cost of a TE when I was in the market. I worked in a MB shop in High School, it got me hooked on the star, that guy has been into WVO for a long time. It is awesome, get ready for great power, cheap fuel, and a quieter engine.

BTW, he has found that heating the oiltank is not good, in the sense that preheating all of the oil over and over again can harm the combustion properties of the oil. FYI. He has a system that uses a coolant/oil/coolant return line bundle that goes back to a tank as a way to heat the oil in the secondary fuel lines.... anything is better than dino diesel.

cdw904

I was hooked on the star after I drove a 1983 300D in high school. WELL BUILT which is a very important attribute to an engineer

I am very glad to see that systems are successful without heating the tank. I had the same thoughts on "cooking" the WVO.

My plans are to place a glow plug fuel line heater in two locations; Right after the supply selector valve and right after the WVO tank.

I can heat fuel that was sitting in the WVO supply line AND heat it as soon as it leaves the tank.

Anybody have any experience with electric (glow plug) fuel line heaters?

myfirstbenz

That is exactly what this guy has done with his system. He also has an electric "blanket" around the aux fuel filter in the engine compartment.

lkchris

Please post your VIN so we can add to list of cars to never purchase.

myfirstbenz

^^^ Ouch

cdw904

lkchris,

I wouldn't sell it to you anyway. I take pride in my work! I also got my B.S.E.E from Penn State with a 3.87 GPA. I am a aerospace engineer by profession. I am MORE than capable of a "simple" project like this. I work on COMPLEX weapons systems; this is nothing. It seems that it is just hard for you to understand Thanks for your asinine comment though.

Saijin_Naib

Dude, if you can do this, please, please explain and break it down here. This would be a huuuuge help. Plus, waht do you think about the hydrogren kits for fuel cars? the ones that hydrolize water into H2 O2 (browns gas) for an additive? Sounds good or not?

Kestas

Hydrogen kits are a gimmick - nothing more. It smatters of a perpetual motion machine. If you think you'll get more energy from the hydrogen than the parasitic energy it takes to produce it by your engine, then you need to go back to school and relearn some fundamentals.