Pre-Fliter for "Algae" Removal from Fuel?

LMJ

Veteran Member
Joined
Feb 22, 2010
Location
Virginia
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2000 VW Golf
Yesterday I confirmed "algae" in my MK4 fuel tank. My plan to determine if it's causing the engine to occassionally shut down is to add a clear pre-filter ahead of the main filter. If the frequency of shut downs is reduced, then I'll know that the "algae" is the cause. Plus I could see any collection of junk in the cheap filter, etc. (I realize that a better test would be to isolate the main fuel tank and connect a second one with new fuel, but the car doesn't shut down very frequently and has never shut down while idling so I"d need a 10 gal second tank to do this test, and that isn't practical.) At any rate, are there any cons to placing a small fuel filter in front of the main one. Will it even remove the "algae" considering that "algae" is getting passed the main filter.


Untitled by Larry Johnson, on Flickr
 

tadawson

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Jun 14, 2013
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Lewisville, TX
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2013 Passat TDI SEL, 2015 Passat TDI SEL
And the reason you don't just remove the bad fuel, clean the tank, and perhaps treat with algacide is what again? Your plan has everything but a bowl of birdseed in it, and seems very misguided to me . . .
 

compu_85

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Springfield VA
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... None :S
The clear prefilters 80s Mercedes use fit perfect on a Mk4:



IDParts sells them and so do lots of other vendors.

-J
 

ZippyNH

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Southern NH
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2015 JETTA TDI SE
Drain the tank...you can skip this step...but it might cost you some filters...algee grows in water...so you have contaminated fuel to start...
Re-fill with good fuel...then treat the FULL TANK OF NEW FUEL to kill the remains algee...
Plan on changing a couple of fuel filters....there will be dead algee residue in the fuel system.
Good algicides include

http://powerservice.com/psp_product/bio-kleen-diesel-fuel-biocide/
BIO KLEEN DIESEL FUEL BIOCIDE
A diesel fuel biocide.
This dual-phased (effective in both diesel fuel and water) biocide kills microbes in fuel, including bacteria and fungus. Use this product to rid your fuel system of microbial contamination.
 

turbobrick240

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Nov 18, 2014
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maine
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2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
Man, that fuel looks like pea soup. I also suggest draining the tank completely and treating with a biocide/algacide. And maybe get your fuel from a different station with faster turnover. The inline filter sounds like a good idea to keep an eye on things.
 

Nevada_TDI

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Reno, sort of...
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I agree, empty the tank before you do anything else. There are no good reasons to not drain the system. You could be chasing gremlins for a long time if you try to band-aid it and not get the water and gunk out of the tank first.
 

Ol'Rattler

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PNA
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And the reason you don't just remove the bad fuel, clean the tank, and perhaps treat with algacide is what again? Your plan has everything but a bowl of birdseed in it, and seems very misguided to me . . .
Some folks should not do their own maintenance. What they will do is rationalize a fix based on mechanical fact that only exists in their head.

Tad, your fix is 100% right on.
 

1854sailor

Resident Curmudgeon
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Baltimore, MD and Westerly, RI
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A little tough love here, guys?

To the OP, just drain the bad fuel out of the tank and use a biocide as has already been suggested. I also recommend finding a different source for fuel if this is what you are getting at your current station.

Good luck and report back.

And the reason you don't just remove the bad fuel, clean the tank, and perhaps treat with algacide is what again? Your plan has everything but a bowl of birdseed in it, and seems very misguided to me . . .
Ol'Rattler said:
Some folks should not do their own maintenance. What they will do is rationalize a fix based on mechanical fact that only exists in their head.
 

n1das

TDIClub Enthusiast, Veteran Member
Joined
Jun 11, 2002
Location
Nashua, NH, USA
TDI
2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
Yesterday I confirmed "algae" in my MK4 fuel tank. My plan to determine if it's causing the engine to occassionally shut down is to add a clear pre-filter ahead of the main filter. If the frequency of shut downs is reduced, then I'll know that the "algae" is the cause. Plus I could see any collection of junk in the cheap filter, etc. (I realize that a better test would be to isolate the main fuel tank and connect a second one with new fuel, but the car doesn't shut down very frequently and has never shut down while idling so I"d need a 10 gal second tank to do this test, and that isn't practical.) At any rate, are there any cons to placing a small fuel filter in front of the main one. Will it even remove the "algae" considering that "algae" is getting passed the main filter.
Untitled by Larry Johnson, on Flickr
STOP! STOP! STOP!
:eek: :eek: :eek:

Fuel that badly contaminated will take out the HPFP in a CR TDI in no time at all. :eek: Fortunately your Mk4 TDI has a more robust fuel system but it will send your injector pump to an early grave. A single tank of bad fuel like what you have is all it takes.

Drain that fuel outa there ASAP before doing anything else and replace it with fresh fuel from a high turnover station. Put a biocide thru it as recommended and be prepared to do several FF changes to catch all the dead critters in the fuel.

Not shouting but CHANGE WHERE YOU FUEL UP! :eek: A single tank of water contaminated fuel like what you have is all it takes to do a lot of injector pump damage in a short amount of time. Fuel up ONLY at high diesel volume / high diesel turnover stations to get only the freshest fuel in your area. Busy truck stops along major routes are best due to the heavy truck traffic. Go where the big rigs go. The fuel is the freshest in the region and will be the least likely to be contaminated with water from condensation and algae growth due to water. Diesel fuel is hygroscopic like brake fluid and likes to soak up moisture like a sponge. Avoiding water is most important during winter months where condensation is more of a problem. It is not uncommon for a busy truck stop along a major route to do more than $30k worth of diesel business in a single day.

My favorite busy truck stop I fuel up at in NH gets 10,000 gallons of diesel fuel delivered every day to keep from running out. They have multiple tanks and have about a 2-3 day supply. An entire tanker truck (10,000 gallons) gets emptied there every day just to keep up with demand to keep from running out. No worries about water at this station because the fuel is constantly being replaced. And if there should ever be a problem with their fuel it will be caught and corrected VERY quickly before a lot of diesel vehicles get damaged.

I have a gas station 0.6 miles from home that has diesel but I purposely DO NOT fuel up there. The station does not get much diesel business because it is not designed to handle big rig truck traffic. They can't get in there to the pumps and the station is always mobbed by gassers. I get a few gallons of gasoline there once in a while for my lawnmower and snowblower. I would rather drive 25 miles to my favorite truck stop instead of fueling up there. Not worth the risk IMHO. While plenty of stations around me have diesel, only a few of them in the area have made it onto my list of "trusted" fuel sources.

No water in diesel fuel means no algae growth and ensures long and reliable service from the injector pump and injectors.

Good luck.
 
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LMJ

Veteran Member
Joined
Feb 22, 2010
Location
Virginia
TDI
2000 VW Golf
STOP! STOP! STOP!
:eek: :eek: :eek:

Fuel that badly contaminated will take out the HPFP in a CR TDI in no time at all. :eek: Fortunately your Mk4 TDI has a more robust fuel system but it will send your injector pump to an early grave. A single tank of bad fuel like what you have is all it takes.

Drain that fuel outa there ASAP before doing anything else and replace it with fresh fuel from a high turnover station. Put a biocide thru it as recommended and be prepared to do several FF changes to catch all the dead critters in the fuel.

Not shouting but CHANGE WHERE YOU FUEL UP! :eek: A single tank of water contaminated fuel like what you have is all it takes to do a lot of injector pump damage in a short amount of time. Fuel up ONLY at high diesel volume / high diesel turnover stations to get only the freshest fuel in your area. Busy truck stops along major routes are best due to the heavy truck traffic. Go where the big rigs go. The fuel is the freshest in the region and will be the least likely to be contaminated with water from condensation and algae growth due to water. Diesel fuel is hygroscopic like brake fluid is and likes to soak up moisture like a sponge. Avoiding water is most important during winter months where condensation is more of a problem. It is not uncommon for a busy truck stop along a major route to do more than $30k worth of diesel business in a single day.

My favorite busy truck stop I fuel up at in NH gets 10,000 gallons of diesel fuel delivered every day to keep from running out. They have multiple tanks and have about a 2-3 day supply. An entire tanker truck (10,000 gallons) gets emptied there every day just to keep up with demand to keep from running out. No worries about water at this station because the fuel is constantly being replaced. And if there should ever be a problem with their fuel it will be caught and corrected VERY quickly before a lot of diesel vehicles get damaged.

I have a gas station 0.6 miles from home that has diesel but I purposely DO NOT fuel up there. The station does not get much diesel business because it is not designed to handle big rig truck traffic. They can't get in there and it is always mobbed by gassers. I get a few gallons of gasoline there once in a while for my lawnmower and snowblower. I would rather drive 25 miles to my favorite truck stop instead of fueling up there. Not worth the risk IMHO. While plenty of stations around me have diesel, only a few of them in the area have made it onto my list of trusted fuel sources.

No water in diesel fuel means no algae growth and ensures long and reliable service from the injector pump and injectors.

Good luck.
Thanks for letting me know what type of damage the junk in the tank could do to my high pressure fuel pump (HPFP). I had to look up that acronym. That gives you some insight into my mechanical knowledge and ability. I'll add biocide tomorrow considering I just filled the tank this morning. Drove it 10 miles to a station with low fuel light on, didn't shut down once..or on the way back. This is a good read regarding "algae"; http://criticalfueltech.com/faq.html

I've had this issue since late winter. Some have insisted that it's my 209 relay. Others say it's the crank position sensor. Just guesses in my opinion. My intent of using the pre-filter was to determine if the "pea soup" was actually the cause of the occasional shut downs. Regardless, it needs cleaning/removing.

I don't have a regular fuel station as most everyone assumes. I could have picked up this fuel at any number of stations in my travels.

Thanks.
 

bobgolf2004

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Joined
Sep 7, 2005
Location
Madison, Wisconsin USA
TDI
2018 Camry Hybrid LE
Thanks for letting me know what type of damage the junk in the tank could do to my high pressure fuel pump (HPFP). I had to look up that acronym. That gives you some insight into my mechanical knowledge and ability. I'll add biocide tomorrow considering I just filled the tank this morning. Drove it 10 miles to a station with low fuel light on, didn't shut down once..or on the way back. This is a good read regarding "algae"; http://criticalfueltech.com/faq.html

I've had this issue since late winter. Some have insisted that it's my 209 relay. Others say it's the crank position sensor. Just guesses in my opinion. My intent of using the pre-filter was to determine if the "pea soup" was actually the cause of the occasional shut downs. Regardless, it needs cleaning/removing.

I don't have a regular fuel station as most everyone assumes. I could have picked up this fuel at any number of stations in my travels.

Thanks.
use a biocide...agree (I use it)
fill up at high turn over station - agree

Be careful about going until your tank is near empty before filling up. If the air that replaces your fuel as you drive is relatively warm and humid, and that air drops below the dew point, water in the air will condense in your tank. The greater the amount of air in your tank, and the more water vapor in the that air, the more water in your tank if the conditions are right for condensation. I noticed you said the above post the your tank was near empty when you filled up.

I'm not familiar with the 2000 TDI, but if you have a fuel pump in your tank, the inlet may be clogged with algae gunk.
 

turbobrick240

Top Post Dawg
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Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
The strain of algae that grows in fuel oil is super tough. All it takes is one tank of bad fuel and it will get a foothold in your fuel system. It will probably take "shocking" the fuel repeatedly with a biocide to get rid of it.
 

1854sailor

Resident Curmudgeon
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Location
Baltimore, MD and Westerly, RI
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Don't bother asking for advice if you're not going to take it. Drain the freaking tank and get good fuel in there, or just go away.

Thanks for letting me know what type of damage the junk in the tank could do to my high pressure fuel pump (HPFP). I had to look up that acronym. That gives you some insight into my mechanical knowledge and ability. I'll add biocide tomorrow considering I just filled the tank this morning. Drove it 10 miles to a station with low fuel light on, didn't shut down once..or on the way back. This is a good read regarding "algae"; http://criticalfueltech.com/faq.html

I've had this issue since late winter. Some have insisted that it's my 209 relay. Others say it's the crank position sensor. Just guesses in my opinion. My intent of using the pre-filter was to determine if the "pea soup" was actually the cause of the occasional shut downs. Regardless, it needs cleaning/removing.

I don't have a regular fuel station as most everyone assumes. I could have picked up this fuel at any number of stations in my travels.

Thanks.
 

White Passat

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Sep 21, 2014
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Austin TX area
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CPO 2013 Passat TDI SEL June 2012 build date Purchased 09/14/14
Your going to need more than 1 filter. I had this issue with my MB, the algae clogged 3 filters after I treated the fuel system.
 

Ol'Rattler

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PNA
TDI
2006 BRM Jetta
A little tough love here, guys?
Well, kind of. My point is that rationalizing a repair based on assumptions rather than fact usually leads to a fix that does not work.

I apologize if anyone got but hurt over my comments.
 

n1das

TDIClub Enthusiast, Veteran Member
Joined
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Location
Nashua, NH, USA
TDI
2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
use a biocide...agree (I use it)
fill up at high turn over station - agree
Be careful about going until your tank is near empty before filling up. If the air that replaces your fuel as you drive is relatively warm and humid, and that air drops below the dew point, water in the air will condense in your tank. The greater the amount of air in your tank, and the more water vapor in the that air, the more water in your tank if the conditions are right for condensation. I noticed you said the above post the your tank was near empty when you filled up.
I'm not familiar with the 2000 TDI, but if you have a fuel pump in your tank, the inlet may be clogged with algae gunk.
What bobgolf2004 said.

A 2000 TDI does not have an in-tank lift pump. Fuel is drawn from the tank by the rotary vane pump on the (rotary) injector pump on the engine. Newer TDIs starting with the PD TDIs in 2004 have an in-tank lift pump.

One thing I do and I recommend others do is whenever either of my diesel vehicles are going to be parked and not driven for more than a couple of days, I always park it with the fuel tank TOTALLY FULL AND TOPPED OFF so there's no moisture laden air in the tank. Over time, diesel fuel will soak up moisture from air in the tank. Moisture condenses on the inside walls of the tank where exposed to (humid) air. Best to keep the walls of the tank buried in fuel and have no air left in the tank. Top it off all the way to liquid at the top of the filler neck.

Have fun! :)
 
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LMJ

Veteran Member
Joined
Feb 22, 2010
Location
Virginia
TDI
2000 VW Golf
whats the best method of syphoning out the fuel to get as much water from the bottom of the tank as possible. Syphon from:
1. the fuel line entering the fuel filter, or
2. the hose connection on top of the fuel tank access under rear seat, or
3. by removing access under rear seat, or
4. fuel tank filler neck.

I'll add biocide after syphoning off 1/4 tank or so of the new fuel that was just added. Then let the biocide do it's job. Have an inline filter lined up and ready to install prior to main filter.
 

tadawson

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If it were me, I'd pull the cover under the seat and remove all fuel/water/yechh, and even try to wipe out as much residue as possible. Change the filter and refill fully with fresh diesel and biocide, and proceed. I can't fathom anything good coming from leaving any of that contaminated gack in your tank . . .

- Tim
 

n1das

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Joined
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2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
What Tad said.

You should also remove the entire fuel sender assembly from the tank and clean it too. All the gook at the bottom of the tank has probably clogged the fuel pickup in the sender assembly.

Hopefully you dodged a bullet with the injector pump and everything will be OK.

Good luck.


Sent from my Nexus 6 using Tapatalk
 

1854sailor

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Baltimore, MD and Westerly, RI
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If it were me, I'd pull the cover under the seat and remove all fuel/water/yechh, and even try to wipe out as much residue as possible...
n1das said:
You should also remove the entire fuel sender assembly from the tank...
Judging by the pic in the first post, it looks like the OP has pulled the sender... :rolleyes:
 
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Rico567

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Central IL
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2013 Passat TDI SEL Premium (Turned in 7/7/18)
STOP! STOP! STOP!
<snip>
My favorite busy truck stop I fuel up at in NH gets 10,000 gallons of diesel fuel delivered every day to keep from running out. They have multiple tanks and have about a 2-3 day supply. An entire tanker truck (10,000 gallons) gets emptied there every day just to keep up with demand to keep from running out. No worries about water at this station because the fuel is constantly being replaced. And if there should ever be a problem with their fuel it will be caught and corrected VERY quickly before a lot of diesel vehicles get damaged.
<snip>
A good criterion for a station to buy diesel fuel, but not the only one. I fuel at a Thornton's on a busy street in Champaign, IL. On my first visit, I could see that there were several pickups, delivery vans, etc. getting diesel, and several times I have had to wait for a diesel pump. There is no room for the big rigs to fuel up here, but they are moving plenty of diesel every time I go in.
The negative indicator is certainly a lack of turnover, but our only experience with bad fuel was gasoline, not diesel. Quite a few years back, we were on our way back from the East coast and filled up our '79 SAAB in Pennsylvania at a truck stop. About 50 miles down the road I started to lose speed, and the car would only make 45-55 mph the rest of the way home to IL— a L-O-N-G drive. A simple fuel filter replacement and the problem disappeared, never to recur. My recollection of that station in PA was all sorts of semis filling up at the diesel pumps, then there was this lonely gas pump I filled up at. As you say, avoid a station with low turnover as a first principle.
 

GWbiker

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Arizona
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In the late '80's, I bought a '77 MB 240D that came with a severe case of Algae. Rotten egg stink. Cure was a complete drain and clean of the fuel tank, both fuel filter replacement and a couple of shots of "Diesel Doctor" into the tank. Had to be done.

Clean Diesel fuel is extremely important.
 

LMJ

Veteran Member
Joined
Feb 22, 2010
Location
Virginia
TDI
2000 VW Golf
... Change the filter and refill fully with fresh diesel and biocide, and proceed. . . .

- Tim
What Tad said.

You should also remove the entire fuel sender assembly from the tank and clean it too. All the gook at the bottom of the tank has probably clogged the fuel pickup in the sender assembly.

Hopefully you dodged a bullet with the injector pump and everything will be OK.

Good luck.


Sent from my Nexus 6 using Tapatalk
Judging by the pic in the first post, it looks like the OP has pulled the sender... :rolleyes:
In the late '80's, I bought a '77 MB 240D that came with a severe case of Algae. Rotten egg stink. Cure was a complete drain and clean of the fuel tank, both fuel filter replacement and a couple of shots of "Diesel Doctor" into the tank. Had to be done.

Clean Diesel fuel is extremely important.
The fuel pickup vessel had to be removed to see inside of the fuel tank. Draining the fuel (and I assume gunk) from the sender seems to have solved my issue, at least temporarily, as the car hasn't shut off once in 90 miles of city driving since then. I do plan to clean the tank after running this tank down a bit. In the meantime, I'm searching for a tank cleaning procedure that I can perform from the top porthole with the tank remaining on the vehicle.
 

turbobrick240

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maine
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2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
You might try sloshing some acetone or gasoline around in the empty tank. Just be sure to remove it all. Maybe dump in quart of acetone and wipe down the inside as best you can with lint free rags.
 

1854sailor

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...In the meantime, I'm searching for a tank cleaning procedure that I can perform from the top porthole with the tank remaining on the vehicle.
I doubt that you'll find a written "procedure" for cleaning the tank. Just pull the sending unit, pump out the bad fuel, wipe up the bottom of the tank with some rags and use a diesel biocide additive in the next couple tanks of fuel.
 

compu_85

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Sep 29, 2003
Location
Springfield VA
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... None :S
I would say adding a clear prefilter is a good idea after cleaning the tank up and treating with biocide. It will let you know if more garbage is still coming out.

-J
 

LMJ

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Feb 22, 2010
Location
Virginia
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2000 VW Golf
You might try sloshing some acetone or gasoline around in the empty tank. Just be sure to remove it all. Maybe dump in quart of acetone and wipe down the inside as best you can with lint free rags.
I doubt that you'll find a written "procedure" for cleaning the tank. Just pull the sending unit, pump out the bad fuel, wipe up the bottom of the tank with some rags and use a diesel biocide additive in the next couple tanks of fuel.
I won't be doing any sloshing. I'm not comfortable with removing the tank. Just don't have the means. I'll look into using acetone to wipe out the inside.

I don't need a written procedure, just looking for "how-to" from someone that's actually done it before and know what they're doing. There's been lots of suggestions to "clean the tank", but nothing describing how to do so, except drain it and use biocide.

I might order a new fuel pickup just in case I damage mine during cleaning. I'm not going to open that port hole up but once more.
 
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