Is it possible to coke biodiesel in the fuel lines? Plugged filter screen again!

[WarWagon]

After a loss of power yet again I dropped the pump screen and find it looks just like the black round screen in this picture - AGAIN!



I replaced the fuel tank several months ago as the insides looked like this.



The stuff in the screen is gritty, yet, will smash down if crushed. Not magnetic. It looks just like the buildup in the bottom of the deep fryer. I have enough biocide in the system... Running B99 from a local commercial refiner in more than one vehicle.

Only thing I can think of is the passenger side injectors are getting too hot with the turbo blanket and all and overheating the biodiesel till it cokes. The 6.2 injector angle heads I have makes this especially tight.

The main FFM filter really did not look bad at all.

Ideas?

 

[NVW]

Isn't the turbo blanket supposed to keep the heat in?

My thoughts were to try a different supplier but you said the FFM is good.

 

[WarWagon]

Oh, the fuel goes through a 10 micron filter before going into the tank.

If the blanket keeps heat in I suspect the turbo and manifold are hotter on shutdown. I suspect shutdown is when things cook.

 

[NVW]

Is it possible that bio breaks down more the #2 diesel?

 

[Burning oil]

I would get a simular build up on my pump screen running on WVO, it was a greenish color (like the color of old copper).

As far as the lines coking I would'int think they would. WVO for example withstands 300-400* in the fryer, but its in a large volume. a small volume would be easier to coke up though. Just dont see it being the problem or seems as if it would be common knowlege??

 

[WarWagon]

Going to add a Cat spin on prefilter and treat for bugs in the fuel. Probably going to keep this one on #2 diesel from now on. Everything should be dead with a new tank and treatments, but, something else in the system may be still contaminated and reintroducing the bug issue. Or is is leftover debris from the bug issue. I will check the fuel heater in case it is melting down.

Other than leftover bugs or excessive heat I am out of ideas.

 

[JMJNet]

I don't think you need a TurboBlanket in AZ unless you live in higher elevation of that state.

It is preety much hot all the time, even in the winter time.

BioD can eat up the hoses also. It is a very strong cleaner/solvent.

 

[Burning oil]

.

BioD can eat up the hoses also. It is a very strong cleaner/solvent.

That could very well be the issue. Good thinking JM

 

[curt]

I would lean towards JM's hose thoughts, Have run and made Bio since 06 and got over 100k on blended and non blended (winter needs to be cut to keep going) and have not had a "coking" problem, or filters for that matter.
I have had some settling in the filter canister but not to the detriment of the elements and nothing that could not be cleaned out, and the tank I did have to pull for filler neck problems had no build up inside so the slosh must take care of that.
Have had one instance of some emulsion that got into a tank but the stuff on War wagons screens looks like hose or the like so maybe the fuel filler neck?
curt

 

[schiker]

Hose material is a suspect. WW are you towing for long periods and the fuel isn't cooling off. Maybe staying hot for a long time recirculating? And its breaking down more than most people?

 

[schiker]

AZ heat and extended high underhood temps? Leting the tank get too low before fill up (coupled with high heat tows??????) Maybe a fuel cooler in the fuel loop return or going to engine might help???

Isn't the black color on fuel filter the Asphilates ???? in the fuel droping out from hot fuel? At some changes I have had some black stuff on my filter media but never that bad or big chunks.

 

[WarWagon]

I am finding that once you have a "bloom" of bugs in diesel it is hard to get rid of. Hoses for the most part are fine. Tank bottom had cottage cheese sludge like build up like was caught in the screen. Same color as the old tank in the picture.

So I am leaning toward another bug bloom that I caught sooner than the last big bloom.

I have the "new" tank out and the FFM off both being cleaned up.

 

[JiFaire]

We had an old Kenworth that caught the bugs once; took absolutely forever to get everything killed, cleaned, and back to normal. Bio may make that problem even worse, not sure.

Keep at it, WW, and thanks for posting! This is a topic nobody seems to know about until it happens to them.

 

[WarWagon]

We had an old Kenworth that caught the bugs once; took absolutely forever to get everything killed, cleaned, and back to normal. Bio may make that problem even worse, not sure.

Keep at it, WW, and thanks for posting! This is a topic nobody seems to know about until it happens to them.

Amen to that! Google is useless unless you want the snake magnets for related info on how to deal with the problem. About all it shows you is examples of what the muck looks like and I managed to find a picture of what I have.

I have been using FPPF Killem biocide. This kills the stuff, but, the mess they make is still around. And killing them also adds to the muck. Shock should be 1920 gal of treatment in 250 gal... My transfer pump filter got changed and was nasty after sucking the fuel out.

Anyway I cleaned the tank best I could and the FFM out. I put in a Fram canister filter before the lift pump and may revisit that solution with a better one. I half expect the bugs and bio to FUBAR it. Cat filter heads have special threads that I didn't get when I was there...

The important lesson on here is to clean out the FFM as well as the tank and keep treating the vehicle for long time. We will see how that works anyway.

 

[curto]

Have you changed your fuel system so that you are not sending hot BIO back to the fuel tank ?

I think you would be better served putting in a 3 way solenoid so you can loop the fuel return at the IP and stop hot BIO going back to the fuel tank.

Craig

 

[guybb3]

I think it's bugs. My bug infection looked the same color but was slimy, not gritty. I have poisoned my fuel ever since and that was years ago.

 

[Burning oil]

Have you changed your fuel system so that you are not sending hot BIO back to the fuel tank ?

I think you would be better served putting in a 3 way solenoid so you can loop the fuel return at the IP and stop hot BIO going back to the fuel tank.

Craig

All you need to do is plumb the return to the suction side of the lift pump.

 

[Husker6.5]

Man, sounds like Trouble With Tribbles! Now you got me thinking, my '94 has been sitting for almost 4 years awaiting the new heads and top end rebuild (3+ year delay due to TWO reconstructive shoulder surgeries (SLAP lesion and torn biceps tendon for one, torn rotator cuff while rehabbing from first surgery for second) on my left shoulder since the injury in September of '08, and the fact that I can't lift over 40 lbs with my left arm now) with a partial tank of Low Sulfur Diesel (about 7 gallons in it) that has sat the whole time. I know back in the day the sulfur eating bacteria would have a hey day munching and breeding on the old high sulfur diesel if the diesel would sit for a while. Now I guess I'll drop and empty and clean the tank and flush the fuel system through the IP (inj lines are off) as well as everything else I need to do to the motor

 

[WarWagon]

Have you changed your fuel system so that you are not sending hot BIO back to the fuel tank ?

I think you would be better served putting in a 3 way solenoid so you can loop the fuel return at the IP and stop hot BIO going back to the fuel tank.

Craig

Good idea. Maybe a fuel cooler off a Duramax.
The return is for purging air and keeping the IP cool. The injectors can also leak air into the return lines. Air separator could be installed. AZ is so hot that cool fuel isn't possible. So I will have to treat it for a long time.