Bosch VE injection pump purge time

[cocheeze]

Hey there,

I am curious if anyone has ever taken the time to measure how long (either at idle or under driving conditions) it takes the Bosch VE injection pump to purge all of the fuel it has inside of itself, the injector lines, and the return path. I am curious specifically about the non-turbo stock pump arrangement on the C223 and 4FB1 engines.

Essentially, I am trying to make sure that I purge diesel through my system for an adequate amount of time before I shut the engine off after running WVO. I think that giving myself only a mile or so to purge has been causing my IP to still have some WVO in it in the morning when I am leaving for work and might thus be contributing to my recent morning hard start problems.

I know I can just add some ATF to my WVO and put some clear hose on the return path to visually time how long it takes for the fuel system to purge, but I figure that chances are someone here at the forum already knows the approximate amount of time this takes.

Thanks in advance!

Casey

[Dog]

I can not give you an time. I talked to some some that worked on pumps he said if you ever run red fuel there would be residue in the pump and he could tell. So you will not get all of the wvo out of the pump/lines. I do mine by time, manual valves are under the hood truck stopped idling I do rev the engine a little. In the summer I go 2 minutes, in the winter 3 minutes or longer, I live in the south not real cold. My times are based on how it starts the next morning. I do run biodiesel full time and this may be different for diesel. ............Dog

[2sk8]

Mix WVO with some Diesel and problem fixed.

Start with 10% and see how it does. I have used pretty much all kinds of recycle fuels you can think of. Learned many lessons along the way. I found out that mixing in some Diesel HELPS A LOT.

Also how good the waste fuels do depends on the condition of your engine(Compression wise), timing etc. A little static advanced timing also helps.

With very good compression so can run pretty much run anything combustible. If your compression is so so, well you will have starting problems, cocking and so on.

Try mixing with some Diesel and see how you like it.

[cocheeze]

in the winter i mix power service diesel fuel supplement in my WVO tank, which helps thin the oil, provides a bit of a cetane boost, and raises the gel point for extremely cold weather conditions.

the reason i am asking about purge times is that i would like to tune my valve switching times in order to use the minimum amount of diesel as possible without the risk leaving any in the fuel system.

i think that i will just have to use some ATF for coloring and time it myself one of these weekends when i have some spare time. i will be sure to report back once i have the data.

thanks,

casey

[Tigman]

In the past when I was using it in my converted truck I'd usually purge for 3-4 miles which is nothing scientific. There was never any starting issues of any kind for me. I've only burned straight veggie oil in the warner months in Ohio because I don't drive my truck in the winter salt. Hope this helps.