Harsh criticism sought

[RustyCaddy]

Well...have been running on biodiesel about 75% of the time for 6 or so years.  Having had good luck with a tried and true processing method i had the brilliant idea of trying something new.

Anyways, the new method batch of biodiesel had the engine running amazingly smooth and really quiet the first commute to work and back.  Switched back over to purge with straight diesel for a mile or on the way home Friday.

Left it over the weekend and it started fine, idled smoothly and quietly.  Got it out of the driveway and underload and it punked out clouds of thick grey smoke up the block and limped back down the hill to the garage.  It was hit or miss on the accelerator when parked and continued to spew thick grey clouds. This was all on straight diesel with may be some left over biodiesel leftover from the purge cycle.

Had a can of Seafoam so took off the filter, filled a fresh filter with Seafoam, ran it according to manufacturers instructions.  After some up and down the block it seems to have miraculously cleared up.

What would be the most likely issue here.  It is a 107 AG Bosch pump on a 1.6. The injectors? A plugged up out bolt?  The seals wouldn't fix themselves. The biodiesel could have had soap, residual methanol, been underconverted, was holding glycerine or any/all of the above (but wasn't water washed).  Glycerine coking wouldn't clear up ?  A lot of soap could have busted up internal gunk into a semi-combustible sludge i guess?

This is more a pump operation question than about fuel quality (fuel batch was a bust for sure) and you guys are the experts. Any advice and/or a$$ kicking for my stupidity welcome and appreciated!

[ORCoaster]

So my first read of this was hmmm, something amiss in the fuel system.  But then first re read and My thoughts are just what change did you make to the brewing of the said fuel.  That might be more entertaining and enlightening to know before we start throwing darts at you for no good reason. 

So the BRILLIANT IDEA was???

let's start from there.  All other symptoms may relate to that and not some goober dislodged from the pump works. 

[RustyCaddy]

i went from titrating my oil for its acid value to using the 3/27 method for biodiesel conversion percent estimation (which indicate a incorrect value of KOH leading th excess soap).  Then switched from water washing to dry washing with wood chips.  i think the conversion to biodiesel isn't so much the problem as soaps that the wood chip medium just couldn't deal with...but could easily have screwed something else up somewhere too, like greater than 1% residual methanol in the fuel or something.

Anyways, the engine went form amazingly smooth and quiet to a hestitating, no power smokestack and back to normal with the Seafoam treatment.  When running more WVO have locked up a feed pump using pure Seafoam...have also had it happen when cleaning injector nozzles that have run WVO with Seafoam.  So the issues seem different between bad biodiesel and WVO.  Does that seem to make sense?

Something in the pump went very wrong there...but can't imagine what  else could get fouled, stuck open or closed down to cause that much smoke?

[Jetmugg]

Sounds like some kind of problem/interaction between the "new" recipe for making biodiesel and the commercially available pump diesel. 

If you have any of the "new" bio-D available, how about mixing it in a jar with some pump diesel to see if anything precipitates.

Steve.

[RustyCaddy]

That's a great idea...will mix some up in  50/50 proportion after work tonight.

Thanks!

[fatmobile]

Clogged filter.
 Clear fuel lines to and from the pump?

[RustyCaddy]

Well it has been a few days now:

Jetmugg...nothing strange coming out of the mixture of diesel and the homemade biodiesel, it looks clear and bright

Fatmobile...in winter i run the biodiesel off of a heated second tank system which is used in the summer for vegetable oil, so the fuel systems are separate once i switch the valves over and was using a looped return. Checked the old primary diesel filter and it looked pretty clean. There is one of those clear plastic MERC inline filters between the tank and the primary filter (its a MK1 pickup but you probably guessed that already  ) and there is a glass case 100 micron filter right before the injection pump.  All looked to be full of diesel and clear when it started belching smoke.  May be i have forgotten about forgetting to purge the system before shutting it down?  That would be simple but it really started easily and it would have been biodiesel in +40 degree weather.

i drained the tank tonight and will run a soap test and a 3/27 test again.  It weird, i have had several alternate fuel issues before to work through but his one was just plain weird.

Thanks all for the help and kind advice!!

[Toby]

Why are you purging the system of BD. BD is a drop in replacement for dino diesel, after all.

[RustyCaddy]

The biodiesel feed stock has tended to be sunflower oil and/or peanut oil and so the biodiesel gels pretty easily.  The second tank is heated so it can run 100% biodiesel through the winter but need to get it warmed up running the motor on diesel for 5 or so minutes when it is less than around 40 degrees (F).  Its getting to where heating and purging isn't needed and the morning of the problem it wasn't that cold even.

[ORCoaster]

I think I need a longer commute.  I have a 12 extra tank that I put the WVO in but with my three miles to work one way I barely crack 150 on the temperature gauge.  And that isn't even taking any heat away for warming the WVO.  I found that if I ran about 10 miles on diesel that the WVO would warm up to about where it needed to be to flow down the hoses well enough to hit the extra hot exchanger under the hood.  I ran the fuel and heat hoses internally and braided them together to get the oil in the hose to warm like the tank.  Those chilly mornings would be a no start for me if I left much WVO in the IP.  If I did I would have seen your results.  Bogging and smoke like no ones business. 

[air-cooled or diesel]

it could have been that new recipe that left something clogging fuel sys. maybe it gelled?or has something in it that is clogging?&if you need to preheat fuel that can lead to clogging type of probs.put enough treatment in biodiesel?when you fill the tank, or add lubromoloy when you fill. you have dual fuel filters?injector(s)were temporarily clogged?&u ran seafoam thru it. 
go back to the old blend, sounds like you ran on it for a long time, nothing like running for that much longer and so,

[RustyCaddy]

Waited on the tests of the fuel from the tank for a couple of days.  Looks like the fuel was a little bit under-converted and could have gotten more soap out but all in all for use a idi engine it wasn't that bad.

ORCoaster-great point about the similarity between cold starting on this batch of biodiesel and straight WVO.  This engine runs really quiet when using a 80/20 veg oil-biodiesel blend and the engine had been running really quiet.  i don't know why this fuel would have been so bad running given it was low quality but not terrible.

air-cooled or diesel-great point there too, may be the biodiesel heating is polymerizing it or something.  The smell isn't paint-ish at all and the tank isn't insulated (its a big heat sink).  Am going back to the drawing board using the in process post-brew water wash and then a full water wash after settling...hey, it worked pretty well for a lot of miles doing it that one.

One thing that happened on Wednesday that may or may not have been coincidental was that the short piece of 5/16th (approximate) viton hose that went between the reducer of the 1/4 return line to the fuel switching valve broke clean in half circumference wise on a drive in town.  Replaced that with semi-permeable carb line. Some things are just coincidences and others aren't; its telling the difference and why that stumps me.

Thanks for the help and advice!