1985 300D Loosing power on WVO
I recently did the conversion to WVO with the mercedessource kit and things were going well. As I started adding more WVO to the tank and got up to around 90% WVO and 10% Diesel I noticed the engine starting to hestitate after running it for 10-25 minutes. It began by hesitating at 75 on the freeway, every five minutes it would get worse and worse until finally I could only get the car up to 25. The filters looked fine so I tried adding 5 gallons of diesel fuel and the problem started to go away as the diesel got mixed in, acceleration came back.
I noticed though as the tank got lower and lower the problem seemed to return and seemed to be temporarily alleviated by adding more diesel. But then the problem would return again. Now I'm running almost 80% diesel and the hesitation problem is creeping up again.
I checked the final mesh metal filter going into the engine and it is clean. The plastic prefilters by the gas tank and before the big 5 micron filter are also clean. I've been filtering my WVO down to 10 micron using filter bags.
I've read through similar problems and have a few ideas but would like some input:
1) I didn't remove the screen on the auxiliary fuel pump by the gas tank (I doubt this is the culprit but could try removing it anyway).
2) Old tired mechanical lift pump?
3) Air seeping in somewhere?
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Sounds like primary filter
I would begin by replacing the 5 micron Stanadyne filter first. You can not go by how it "looks". If there was any moisture in your SVO this filter will quickly plug up because it is a very efficient water separator! Report back results after you have change the filter element.
Removed the plastic filter in auxilliary pump
I just removed the plastic filter that is in the auxiliary fuel pump and added five gallons of WVO. After about 10 minutes of driving the WVO seemed to get well mixed into the fuel system and the car slowly started to bog down. Eventually it started stalling and died on me a couple times on my test drive.
I will order some new Stanadyne filters and go from there.
Primary Filter
I received my 3 pack of primary filters yesterday and switched out my existing one for a new one. I still could not get the car to start after trying for quite a while. I ended up making two additional changes at once, I drained out all of the veggie oil in the gas tank and put in a few gallons of diesel. I also replaced a line that was a little kinked because it was too short (my mistake). I thought the kinked line might have been causing a problem. The line runs from the mechanical lift pump up into where the hard lines originate.
Once I got the engine started on diesel I took four gallons of it out of the tank and replaced it with about 80% veggie oil so the car is now running on maybe 50/50 blend right now. I'm going to start putting more and more WVO into the tank and see how it runs. Hopefully the kinked line was the problem.
Since the car didn't start right after changing the 5 micron filter I don't think that was the source of the problem. I'm now filtering all my WVO down to 5 micron before putting it into the car anyway just to be sure.
Also check
If you continue to have problems you may want to inspect the fuel tank screen in the bottom of your fuel tank. This can be a common source of power loss problems. The reason the car did not start right up was probably air in the system. Very common after filter changes. Be sure to refer back to the manual on tips for bleeding the air out after filter changes.
Hi Kent, Seems like it was
Hi Kent,
Seems like it was either the filter or a kinked line i replaced. The car starting running great on 100% veggie oil.
Thanks for the help!