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WVO Booster Pump Troubles 1985 300TD

Submitted by William S. Brewer on 6 November 2008 - 8:06am.

I am having problems getting my WVO system to work. It has worked well for over a year (20,000 miles!), but now only works on diesel. I've traced everything out and found that the booster pump (FRB5) back at the rear tank won't pump WVO. It pumps diesel at 10 gpm but only pumps WVO at about 2 gpm. I replaced the pump with a new pump and it works identically. I removed the pump and tested it on my bench with short hose lengths with clean WVO and diesel running directly off of a battery and it is still the same. I don't think that it is temperature related because the problems started on a 100 degree California day. The oil itself appears to be liquid gold and looks good enough to cook in again. The oil itself is not that viscous. I tried a 50/50 blend of WVO and diesel and it pumps at about 4 gpm, which is good enough, I guess. I just hate buying diesel. What is going on? Is there an internal screen that is getting blocked in the pump? I collect WVO from about 4 places. Maybe there is something new in the oil that is bad. The oil is like dark ice tea with no sediment or clouding after settling and filtering. The pump appears to be struggling to pump WVO, with a steady thump thump thump. On diesel it clicks away at a furious pace. I have a pre-filter (the clear ones) before the pump and the pump is new, so I doubt the pump could be damaged.
Any ideas?
Please help! I am considering going back to diesel and selling the WVO conversion on Ebay! My car pool partners are starting to complain.
Thanks,
Bill in Tehachapi

‹ 83 300 SD -Sticky fuel gauge Power loss is less when switched to return on svo 300 SD ›

Things to check

6 November 2008 - 8:20am
Kent Bergsma

Hi Bill, The Boost pump we sell has a internal plastic filter screen. We send out a note with our pumps in the FULL kit that explains you should remove this screen if you are running WVO. You can remove that screen by removing the big bolt on the bottom of the pump. Be careful not to damage the o-ring. Try that and see what happens.

Other things to consider: In the climate you are driving your engine should run on WVO without a boost pump. It may not produce exactly the same power but it should be adequate for normal driving. When you are driving in looped mode only 1.5 to 2.5 gallons are pumped to the engine every HOUR!!!. So even a very low rate on the boost pump is adequate.

Check to make sure your valve switching is working properly. Check the filter screen in the bottom of your fuel tank. If you are still having problems you may have to replace the mechanical lift pump at your injection pump. When these are worn out that can work ok on diesel but struggle when trying to pump WVO.

Hope that helps, Kent

Thanks Ken, That was

7 November 2008 - 7:10am
William S. Brewer

Thanks Ken,
That was it. I pulled out the filter screen and it is giving me about 10 gpm now. I must have missed that note in the kit last year.
Your kits work great!

Bill Brewer