I have an 83 MB 300D with the greasecar kit and I can't get her to run on grease. I think the problem is that I can't get the grease to the IP. How do you prime this side?

The car runs great on diesel, so I don't think that there is anything wrong with the engine. The kit was installed about a month ago. I have checked the plumbing numerous times, it is correct. I have also tested the valves and switch with a voltmeter-everything is working properly. I removed the feed lines to valve "A" and blown air through to test-diesel feed with no power and grease side with switch on. I also, for lack of a better method, hooked up my shop vac to the pex line to make sure I could draw from the grease tank and that was a little messy but worked. I filled the filter with veggie oil and the grease tank has store-bought oil in it.

So, I think my problem is that there is air in that line. I tried using the primer pump (which I also replaced) with the system switched on, but that did not seem to help.

And here is what is really confusing me- if I prime the grease side using the primer pump and then switch over to grease, the car stutters for a moment and will then run. It's a little short on power, but mostly OK. But I can tell from the diesel and grease tank gauges that she is burning diesel. (Doesn't smell like veggie oil at the exhaust, either.) If the system is working, where is the engine getting diesel from?

Thanks for reading all that! Rich

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Rich

83 300D
98 E320 Wagon

I had to install a second fuel pump for the grease to work on my old 240d, after that no more problems.

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1983 240 D-SOLD
1979 300SD

Lonesome-What kind of pump? Where did you install it?

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Rich

83 300D
98 E320 Wagon

Sounds to me like your oil is either too thick for your lift pump to pull it up to the engine, or perhaps the switch-over valve isn't working properly. If you've checked all the line routing and plumbing, we know it's not a crossed hose somewhere... How hot are you getting the oil at the tank or in the lines? That ought to thin it out enough for the lift pump to handle it.

Cheers, John

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'98 E300TD (W210) | Sold 6/09 with 205k and counting
'04 VW Touareg V10TDI

Rude, could you try to take some pictures of your setup for us? keep the file size as big as you can so we can zoom in

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1985 MB 300D/T

Fell off the WVO bandwagon when people started trying to charge $2.50 a gallon for dirty vegetable oil.

Id recommend a couple things 2 you :

1. get some clear tygothane line from mcmaster. Its soo much easier to see what is going on when you can see the fuel!

2. get some fuel dye and dye the wvo side so you can tell the difference between dino and wvo.

3. get a hand held vacuum pump with gage. Verify there are no vacuum leaks between the line going into lift pump all the way back to the line that connects to wvo tank. You will have to plug the dino side of the input valve for this, and ofcourse the banjo bolt must be plugged. you should be able to pull 15-20 in Hg and HOLD it for 10 min or so. If not, you have air leak. With clear hose you will be able to see the air bubbles in lines. Easy to find where they are getting in!

4. last, loop your return if its not already. LP, IP will pull lots of vacuum, but still no reason to send majority of fuel unused all the way back to wvo tank. Loop it back into the supply line for wvo after filter, you will get much more wvo to LP.

You are properly heating the wvo to atleast 160F before switching over, right??

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Paul
Benz-less
I need an SDL !

Where does one buy fuel dye?

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-Dan
1983 240D AT, 163K running on VO, "The Patience Tester"

Thanks everyone for your replies! Paul-I will try to take some photos tomorrow.

Dave-I will order some clear line and a vacuum gauge tomorrow. I found some fuel dye on eBay, but will inquire at local auto parts store. I had an inline thermometer installed, but removed it in fear it was blocking WVO flow. I measured it at the tank and it was only 107. But I don't believe this is the problem right now-I only put in 4 gallons of store bought veg oil first. I was given wrong info on switch from installer, so was running on purge at first. Also, I ran a 5 minute purge today at the recommendation of a post on Greasecar. So, it's mostly diesel in my grease tank anyway.

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Rich

83 300D
98 E320 Wagon

You shouldn't need an extra fuel pump. I tried this and it worked for a while, but then the pump burned out. This happened with 2 different pumps. The pump is just a crutch that overcomes another problem in the system. The Greasecar system has a defect in its design. The looped return line causes air to become trapped in the system. I solved this, and eliminated the need for the extra fuel pump by installing a "partial return" line. It allows the air to escape back to the veg tank, but allows most of the return fuel to get looped back into the supply.

Good luck!

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1987 Mercedes 300D ~200K (Greasecar & Biodiesel)
1993 Ford F-250 7.3 IDI diesel 165K (Biodiesel)
1996 Thomas/International Bus with DT466 engine

Rich,

a shurflo diaphrama pump works perfect. Placed near tank it will switch on and off depending on pressure, there is a pressure switch on the pump. I installed a lamp to be informed when it is running.

Tom

Dan- How is your partial return loop routed?

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Rich

83 300D
98 E320 Wagon

I cut into the return hose that loops from the return solenoid back to the supply hose that comes out of the pex leading to the veg filter. I installed a "T" in the line, with the 3rd port aligned vertically so that air will bubble up, but fuel will continue on its usual route back to the supply. On the vertical outlet of the "T" I installed a needle valve to control the amount of opening, and after this a bit of clear hose, so I can see how much fuel is getting returned with the air, and then this hose goes into pex, which is routed back to the veg tank. I found this design on another WVO forum, and it is working great for me.

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1987 Mercedes 300D ~200K (Greasecar & Biodiesel)
1993 Ford F-250 7.3 IDI diesel 165K (Biodiesel)
1996 Thomas/International Bus with DT466 engine

I'm curious to see how you did this as well.

So Rich, it seems that you were running in purge mode when you thought you were in veggie mode, that would make sense that your diesel gauge was going down instead of your VO tank. I'm not sure how the greasecar system returns fuel to the VO tank though, is it backflushing the supply line or is there a dedicated return line?

If the purge mode backflushes the supply line (and filter) then you should have all the air pushed out of the line by now and should run fine in VO mode...once you've got the switches straightened out.

If you have a dedicated return line, you can temporarily connect the VO supply line to the return line coming off the diesel filter and run in diesel mode for a few minutes. This will backflush and purge the supply line and filter.

If you still have problems with stuttering and low power, you most likely have an air leak. And I agree with Dan, the stock lift pump is adequate for pulling fuel from the VO tank and through the filter if all is heated well. You should need an additional fuel pump.

Good luck and let us know how you make out.
-Geoff

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1985 300TD-euro 352,000 mi
1974 240D (1?)52,000 mi - has a new home now

Thanks for the description...
Is there a check valve somewhere? The supply hose is under negative pressure and would pull air into the fuel line from the tank unless you have another pump before the filter.

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1985 300TD-euro 352,000 mi
1974 240D (1?)52,000 mi - has a new home now

Geoff- The purge mode flushes back through the supply line all the way to the VO tank. Ran it that way for 5 minutes and still not burning any grease.

Dan-that return loop sounds good. Are the "T's" available at auto supply stores?

I have photos to post, but don't know how. Anybody point me to a link?

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Rich

83 300D
98 E320 Wagon