Tan Junk in the Fuel - What is it and how is it getting in

[mcwho]

In a related post I blamed the carburetor,

http://thefactoryfiveforum.com/showt...S-Blues-(1806)

The Carb is not at fault as I have siphoned off the fuel from the float bowls and find this tanish colored grit. There are 2 filters, a in line clear case one by the fuel pump, and a final one that is of a Russel design just before the carb.

The symptoms were that it would not idle and when I blew out the idle circuit that helped.

These pics are the float bowls and the fuel in a 3" mason jar for perspective.

[Gumball]

Is the Russell filter one that has a sintered bronze element? If so, any chance that the material you are finding is some of that element breaking down and making its way into the carb?

[mcwho]

Gumball,
Yes, I have added pics of the filter, they show up as links. It does resemble the sintered brass element to some extent.

[mcwho]

I did find a 'service alert' on a site related to sintered fuel filters. IN that forum they are talking about the filter clogging due to the fuel breaking down the filter, not necessarily a related issue.

http://www.trikepilot.com/forum/topic/718

I have never heard of this issue but will research.

[mcwho]

I found a link on the RUSSELL site that states that these sintered brass filters are for engines that produce less than 300 hp.



http://www.russellperformance.com/mc...-filters.shtml

[GoDadGo]

Wow!
Didn't See That One Coming!
I Had Now Clue About This Style Of Filter Being Problematic!
Thanks McWho & Gumball!

[NAZ]

This slightly brownish amorphous substance looks like biological fouling. If seems to settle near the bottom over time and is a bit slimy to the touch I'd bet that's what it is. It's way more common in heavy fuels such as diesel, Jet A, and kerosene but I've seen it in gasoline too. Ethanol blends and sometimes additives in the gasoline promote bug growth under the right conditions and warm weather accelerates the process. You'll need to first look for water in the gas and eliminate that as it promotes bug growth. If you get straight gasoline with no ethanol you'll find any water at the bottom of the tank as gas doesn't mix with water. If you get a blend of alcohol such as E10 or greater it will most likely be in solution and you won't find it at the bottom of the tank as alcohol is hydrophilic and readily absorbs even moister out of the air. Next you need to treat the gas with a biocide specifically formulated for fuel. If you routinely pump an ethanol blend (or if you have a diesel powered truck) you will need to routinely treat your fuel like at every oil change to ensure you keep bug growth in check. These biological colonies grow rapidly and when they die they are acidic and tend to corrode things like tanks, fuel lines, carbs, and such. Once treated expect to change the fuel filter(s) as they will tend to collect the contamination.

[mcwho]

I went back and pulled this stuff out of a pocket in the bowl on the passenger side front. Using a q-tip and a screwdriver I got another whole wad of stuff that looks like a cinnamon or brown sugar color, it does look biological in nature.

[NAZ]

Great photos. The last two look like grit but how would that get past the filter? Does the contamination feel gritty or more like a jell when you rub it between your fingers? If it's microbial it should feel kind of slippery or pasty when rubbed between your fingers. Here's a photo of what bio contamination looks like when left unchecked and turned to jell in the carb. You don't usually find it this bad unless the vehicle has been setting for a long time. These microbes thrive in small amounts of water that enter the gas tank through condensation. There's not much you can do to prevent condensation especially in humid climates but keeping your tank full helps to minimize it. The condensation forms on the fuel tank walls and ends up as a water phase at the bottom of the tank. That's why the microbes seem to stay in a lower phase -- their hanging out in the water phase. A full tank minimizes the surface area of the tank walls that condensate form on.
IMG_0671.JPG

[first time builder]

Alcohol fuel contamination, very common now !

[CraigS]

I have been using this in the boat for about 5 yrs. The XP.
http://www.valvtect.com/marineGasAdditives.asp
Stabil also makes additives. Be sure to pick one that helps deal w/ ethanol problems. I suggest that you drain the tank. Get what you can w/ it in the car and then remove it. I would pour in 6-8 oz of gas or kerosene, shake it all around and then tilt it to pour it out of the filler neck. Maybe a couple of times as this kind of junk typically settles into the bottom.

[Avalanche325]

Also PLEASE take that clear filter out. They are a fire hazard. Especially down by the fuel pump near the headers.

[mcwho]

Yes, I am removing the Clear filter, it is before the mech fuel pump which I have discovered is the wrong place, I am going to put a JEGS labeled Rusel Fuel filter by the carb, will likely remove the sintered brass one as well. I am going to install a fuel pump pressure guage and a check valve as well.

As for the stuff in the carb, it looks biological, my theory is that it hitchhiked in some water that was I the gas, and then grew and multiplied, that would explain how it got past the fuel filter, both of them. It feels slimy when in the fuel and looks like cimmanon when dry.

[NAZ]

OK, sounds like you cracked the code on the contamination. If you do a search on line you'll find some products that claim to deal with biological contamination in gasoline. Several claim to suspend the microbes in solution where they will either get burned off or filtered out. I have no confidence in these. However, I know for sure that biocides are effective. Working as a Chemical Engineer for Anheuser-Busch, I oversaw the use of biocides every day to keep bug growth in check in our soluble oil coolant systems. Find one that says it's formulated for gasoline (these are usually also good for diesel) and use as directed for a shock dose. You don't want to creep up on this you want to treat the system with enough of a dose to kill ALL of the bugs. Once your confident there is no water in the system and the bugs are dead try to keep your fuel tank full as much as possible and you will likely never have the problem again. But if you do, you'll know how to deal with it. Good luck!

[mcwho]

Yeah, I am pretty sure its biological, ia have a sample saved in case I find someone with one of them Spectrum Analyzers or whatever they are called. Really, I will always us a fuel stabilizer from now on on that roadster.

[bobl]

Carburetors are vented to the atmosphere. If they are stored with ethanol fuel in them they will attract water just sitting there in a humid environment. It's best to come up with a way to drain the float bowls if storing. Ethanol fuel treatments will help, but they will still attract water and that's what does the damage.

I owned a marine business for many years. A few years ago we had a beaker of fresh e10 gas sitting on a work bench with about 16 oz in it. It was raining outside and we had some fans blowing in the shop, so conditions were ideal. I looked at the beaker and you could see water forming on the inside and being absorbed into the gas. After a few hours it phase separated and there was about an ounce of pure water sitting in the bottom....ethanol fuel is some really bad stuff around water.

Bob Lloyd

[mcwho]

Bobi,

Interesting note. Had a boat years ago with water fuel separator, has any of these type of products migrated to the auto industry? Especially in Hot humid climates like Florida. I did a google and it looks like the same products I used to see in West Marine and Boat US. VERY LARGE !

[CraigS]

In the boat we have a Yamaha brand water seperator filter. Huge dang filter. I put a new one in each spring and also use the above additive in all our gas. its not too bad $ wise as it only needs one ounce per 10 gal of gas. I think the problem w/ the boat is all the sitting. I pump the tank dry each fall, but even in season, the boat often sits for 3 weeks and the 30-50 gal of gas is just sitting there too, absorbing water like bobl explains.