Mountaineer gas tank fill question

[rodandkyn]

This could be in the wrong forum, so please advise........

I have a 2002 Merc Mountaineer. I've been adding Lucas fuel treatment to each new gas fill. The styrofoam seal at the top of the fuel treatment bottle "could" have gotten into the fuel fill line. I'm not for sure about this, since the seal is now missing, and I can't find it, but I've lately noticed that I have an extremely slow gas fill issue. The fuel nozzle will kick off if much of a flow rate is present. I disconnected the gas fill downtube, cleaned it completely, and have disconnected the hose going to the tank. Since these orifices are quilte large in diameter, I don't suspect them to be the issue. I noticed that when the full fill hose is disconnected from the gas tank, there's a backflow preventer plunger that when depressed will let gas flow out of the tank. Could the styrofoam seal have gotten somehow behind this plunger and doesn't let gas properly flow into the tank?

Thanks,

Rod

 

[jayton]

This could be in the wrong forum, so please advise........

I have a 2002 Merc Mountaineer. I've been adding Lucas fuel treatment to each new gas fill. The styrofoam seal at the top of the fuel treatment bottle "could" have gotten into the fuel fill line. I'm not for sure about this, since the seal is now missing, and I can't find it, but I've lately noticed that I have an extremely slow gas fill issue. The fuel nozzle will kick off if much of a flow rate is present. I disconnected the gas fill downtube, cleaned it completely, and have disconnected the hose going to the tank. Since these orifices are quilte large in diameter, I don't suspect them to be the issue. I noticed that when the full fill hose is disconnected from the gas tank, there's a backflow preventer plunger that when depressed will let gas flow out of the tank. Could the styrofoam seal have gotten somehow behind this plunger and doesn't let gas properly flow into the tank?

Thanks,

Rod

ok, I'll shoot...

Hello Rod, the first question I would have to ask, is why in hell would you be adding a bottle of fuel treatment to EACH fuel fill. The injectors of today are designed so that they do not get clogged, and do not ever even need to be cleaned. If you did have some sort of build up that is causing you a problem, fuel treatment is not going to get you out of trouble.

If you are adding the fuel treatment as a preventative maintenence, then you are going way overboard. You would get the same level of clean for your injectors by putting the treatment in every 10th fill up. It seems to me, that over a period of time, having a fuel additive always present in the system 100% of the time would actually have a negative effect on something in the future. Does the Lucas Oils co. even recommend that kind of interval themselves?

If anything, by adding the fuel treatment in there all the time, you have increased the number of opportunities for something to go wrong, such as dropping in styrofoam seals, by tenfold.

Where you able to check the other little rubber tube for obstructions? It may just be that a particular gas station has crappy pumps. Have you had the same results at several gas stations? I would have to say that it is possible for that little piece to get caught up in there to cause you problems. It isn't likely that the fuel pump is going suck it in. If it really is in there, I don't think that it is likely it would break down and disappear since it is styrafoam. If you can't get to where you think it may be stuck now, then I would ride it out for for 2-3 more weeks to see if anything changes before I would start ripping the tank out. That can be a pain in the ass.

 

[gijoecam]

There may be an inlet filter at the tank filler neck. The easiest way to check would be to run the tank as empty as you can, and pull the filler hose off the tank end. It sounds like the paper cap seal may have fallen down in there and gotten stuck in the filter screen (it's basically a rock-catcher) or the anti-siphon device if there is one on there. (They had 'em on the 2nd gen Explorers, not sure about the 3rd gens)

-Joe

 

[rodandkyn]

Hey Jayton and Joe.....thanks for your replies!!

Jayton - I may have misrepresented the Lucas treatment. The following is from their website and is what's printed on the bottles:

"A powerful blend of oils and additives that contain no solvents. Designed to increase power and fuel mileage and also lower exhaust emissions through a more complete combustion.

Lucas Fuel Treatment is formulated for both gasoline and diesel engines, carbureted or fuel injected. It gives your fuel system what it really needs - a blend of super slick oils and additives with a high detergent action that allows the engine to operate at maximum efficiency. Also, it cleans and lubricates the carburetor and injectors and causes the fuel to burn more thoroughly for increased power and less fuel consumption. Lucas Fuel Treatment should definitely be used in vehicles that require leaded fuel because it actually replaces the benefits of lead in gasoline without causing harmful emissions. Use it to pass smog tests. Finally, it totally neutralizes the harmful effects of low sulfur diesel fuel."

A .pdf with more info.... http://www.lucasoil.com/images/medialibrary/fuel_treatment.pdf

And I contacted Lucas to make sure I wasn't overusing the product and they indicated it would be safe for every use, but perhaps you're right and I'm pouring money down the tank.

As for the other, smaller tube.....there's actually TWO more smaller tubes at the filler neck......one attaches to the vent section of the filler neck and the other just appears to be capped and tied off up near the filler neck. It may be a vent cap @ the end instead of a sealed cap......I didn't check that. I blew into the vent tube that's connected to the filler neck, and it appeared free of obstruction. We've had the issue for ~1.5 months, and it's repeatable at multiple gas stations.

Joe - I actually removed the aluminum filler neck in its entirety and cleaned it from both ends......I was able to pass a portion of paper towel through it, so I don't believe mine has the screen. That SURE would have been nice, though!

Again, I'm not ABSOLUTELY positive that the fuel treatment seal went down the pipe, it just seems too concidental, but I was wondering if there's ever been experience from anyone else that the backflow preventer started sticking or slow to operate causing the same problem. It's good to hear that the fuel pump probably wouldn't try to suck it through, but now I'm a bit paranoid that it could clog the fuel inlet to the fuel pump and have the car stall.

I'll let the fuel run all the way down and try to look more thoroughly into the tank inlet to see if there's a way to get the backflow preventer piece out for inspection........

Thanks again, you guys!!!

 

[gijoecam]

I wasn't clear... By 'filler neck' I meant the neck on the tank. I wouldn't be worried about the piece bolted to the body as it's just a tube. It's the other end of the flexible hose I was referring to, at the inlet of the tank. (On the assembly line where they make the tanks, that piece is referred to as the filler neck).

As for the pump sucking it up, it's nothing to worry about. Even if the piece was to somehow find its way to the pump, the pump inlet is protected by a pre-filter that's generally pillow-shaped, and about 2" by 4". That one piece of paper/plastic/foam won't be anywhere near large enough to do any harm. If we were talking about something the size of a plastic bag, then maybe I'd worry, but for that, even if it's in the tank itself, it's nothing worth worrying about.

As for the pumping issue, I'm almost wondering if it's something else... I'd have to look at the evaporative emissions diagrams first, but off the top of my head, if the vent solenoid was stuck closed, when pumping gas, the air would have noplace to go, so the pump would react like that. It could be coincidental, or may be related... tough to tell from here. Obviously an obstruction in the inlet would manifest the same symptoms, so narrowing it down over the 'net is, obviously, difficult.

-Joe

 

[rodandkyn]

ahh, gotcha, Joe.....thanks a ton.