Crap in Fuel Tank (and Carb)

[bobinyelm]

Ever since putting my BDR together I've been plagued w/ black grit in the carb.

The car has only 50mi on it, but I have now disassembled the carb almost a dozen times to clean the bowls out, and now have THREE inline filters in the fuel line, and I just got enough again (maybe last 10mi since the last filter installed) that some cause the float valve to hang flooding the engine (again).

Am I the only one, and if not what type/brand filter finally stopped the stuff? I have 3 different brands (round w/ 3/8" fittings) hoping one would be better than the other, but so far, none have stopped the stuff.

I have one between the tank and the electric boost pump right by the tank, one after the elec pump, and one right before the mechanical pump, and another between the mechanical pump and the carb.

The stuff is very fine, is not rust, and is black. I believe I tried a magnet once, and it's not magnetic. I drained the tank (via the plug at the back), hoping the flow velocity would clear the stuff out, but no-go.

I get tired of having to keep the choke on the fast-idle cam at the end of every drive to keep it from loading up and stalling.

Thanks,
Bob

[FWB]

its rubber hose.......the ethanol in the fuel is breaking down. i'm plagued by it too.

[Dwight]

three fuel filters will choke it down. You need one large paper filter, that is all. Make sure the in and out tube on the filter is 3/8" or large.
With three filters and a small fuel line you can idle but when you rev the motor it will starve out.
and ethanol gas is killing our carb'ed cars, lawn mowers, weed eaters, chain saws, any small engine. I hate the stuff. I'll drive across town to buy non-ethanol gas.
Like FWB posted it will eat older rubber and some of the plastic and gaskets.

Dwight

[rpatton3]

If that is the case, get an app for your smart phone for places nationwide that sell ethanol free fuel. Puregas.org is one and it is free.

Crop dusters and marinas are good places to look, too.

[bobcowan]

Unless you installed some really cheap or really old rubber hose, that doesn't make sense. E10 has been around for a long time - like 1-2 decades. And yet nobody else has this problem.

You should be able to install one filter near the carb and call it good. You drained the fuel tank, and it was clean. So it must be coming from the lines or the pump.

Remove some of the rubber line and cut it open; see what the inside looks like. Put it in a jar of gasoline for a few days, shake it up every once in a while, and see if it softens up and deteriorates.

[mln385]

Change your fuel line to PTFE type (teflon) this does bring up an interesting question. How do the new BDR tanks hold up to Ethanol fuel?

[patrickt]

Originally Posted by bobcowan

Unless you installed some really cheap or really old rubber hose, that doesn't make sense. E10 has been around for a long time - like 1-2 decades. And yet nobody else has this problem.

I agree with you, Bob. All of the Gates fuel line hose at my favorite little auto parts store is ethanol resistant -- I don't think you can even buy fuel line hose that is not ethanol resistant. Like you said, unless you're just buying crappy old rubber hose it just doesn't make a lot of sense. Now, the zinc flecking off the carb bowls is a different story, but that doesn't sound like that's what's going on here.

[tirod]

Unfortunately, gas line that isn't resistant to ethanol is still widely sold. It's the less expensive 30R7 sold for "carburetor" use, about $1.29 a foot.

You have to ask for and check to see that it's the new J30R14T2 hose that is ethanol resistant. Gates sells it under the "Barricade" name. It's not cheap. OE moved to barrier hose years ago, the aftermarket is slow catching up.

Be advised - unless specifically labeled, "A/N" hose isn't the new stuff, either. It would be unfortunate to pay good money and then have the "disposable" 30R7 interior liner constantly flaking away to ruin your ride.

OE hasn't used much of any rubber hose in years, the fuel line connections at the tank are nylon tubing, at the engine they have been using fluoroelastomer - "teflon" - with some braided armor. That's not just for the higher pressures of fuel injection - it's because alcohol contaminated fuel is being sold nationwide.

Don't take my work for it: Performance Fuel Hoses - Hot Rod Magazine

Check the deterioration rate of 30R7 hose and how quickly it falls apart.

[mreid]

Any hose lables "for fuel injection use" is ethanol resistant. If you are running braided hose, then upgrade to the teflon lined stuff and your problem will go away. With an electric pump, you should have a filter before the pump (sock if it is an intank pump) and then one just before the carb for the best result.

[Cashburn]

We've seen this occurring in the carb feed lines. That's why filters anywhere in front of it do nothing.

[Trueoo7]

Read this thread and pay attention to the pictures.

Stainless Steel Gas Tank Problem