Running on a two tank system for a bit more then 2 years. I run it on a 1996 Toyota Hilux non turbo. So far my setup is: No heating to vegoil tank, a cross barbed fitting which supply's heated coolant to both heat exchanger and the filter coolant wrap, one pevekoil valve and fully looped return. Recently added a vacuum gauge to monitor filter and oil resistance. I live in a rural area and 2-3 km seems to purge the fuel system enough for a nice start up. Cool to warm winter with rare light frosts(the oil is always liquefied.
I had an IP rebuild once but it had 400,000 km on it any way. Also the injectors. A compression test showed up pretty good.
We got another diesel now which is a 1999 VW polo classic - has a combined mechanical and electronic injection with an ECU(non turbo).
This drives me to upgrade my current conversion on the hilux and install a perfect conversion on the VW.
It doesn't seem I need to heat the vegoil until the engine compartment just from observing the vacuum.
My main concern and questions are regrading on how to handle the return fuel from the IP. From doing some research on the net I understand the returning diesel to the tank serves some or all of this purposes:
- cool down the fuel for a more efficient combustion- less fuel per KM.
- cool it down to keep the lubrication properties high and protect IP internal.
- cool down injectors?
- purge any air that might have entered.
- gathering any impurities around the injectors?
The thing is I think it might not be the best idea to return any fuel to the diesel tank because every time you purge differently, meaning: sometimes you purge when going up hill , sometimes down hill, some times in traffic , etc... You can never be sure you purged vo completely out of the lines and when you get back to diesel you might have some vo go in the diesel tank.
Im thinking of two options:
Option 1- Having diesel and vo looped and only returning to vo tank when purging. Using two valves, concerns are: Heated diesel, although my guess would be that it is insignificant at the beginning of the ride when the engine is still cool and also when purging most people with two tanks would purge with hot diesel that has heated up in the lines/valves/filter while driving on vo. I can always add a few % of Biodiesel for lubrication and monitor air with clear section of hose or/and an inline filter.
Another thing is the bit of vo which would stay in the short section between the return valve and the intake line to the IP so when returning back to looped diesel you will have it draw in(am I clear?)
Option 2- Using three valves to handle both fuels and try to have all the options including return to diesel tank when needed. This would be a lot of plumbing.
What is the most current up to date setup that is recommended?
Also my plan is to have the FPHE and heated filter in series very close to each other so I would think restriction would not be significant.
One last thing, I am thinking of getting one of Elsbets's modified injector tips and glow plugs for the VW since I am worried about injection timing with the ECU and the injector tips should have a good effect on it. Any thoughts about this would be appreciated to.
Will probably add Injector line heaters to the VW.
Any thoughts or comments will be appreciated,