Fuel woes: heavy tinkle out the fuel vapor line and pump whine

[Sebsi]

Hey all, I had a couple fuel related issues yesterday.

It was hot (about 90) and my pillion and I were on a mountain ride up to Mt. Evans. Lots of twists and turns. We eventually hit a major construction zone in the middle of the mountains and had to wait for about 10 minutes. During this time about a cup of fuel just tinkled out my fuel vapor line behind my right peg. I have a recent air accumulator installed. It's let out a few droplets before, but this was a steady stream, kind of like the end of a tinkle. I kept inching forward, but soon had a dinner plate size gas stain underneath. When I shut off the motor it stopped, and started right up again when I restarted. Temp gauge was high, right below the red, and the fan was on.

After we got underway, it seems to have stopped, but I have no way of knowing whether it's doing it when I'm underway. It did not do it again for the rest of the ride.

However, about 20 minutes after the tinkle, the fuel pump suddenly whined, and stayed whiney for about 5 minutes. I had over 1/2 a tank of fuel. It whines when it's very, very low, so this was a new thing.

I have had the bike for 3 months, and have put on over 2500 miles in that period. It's a 93 K1100RS.

Are these two related? It sure seems like it.

Thanks,

Seb

[Grim]

Just think...if you hadnt done the mod that would have ended up in your engine oil.  :yow

Did you just tank up? Do you have the flap removed?

 This is typically due to heat expansion. Might consider a Johnny blanket. It will help keep the to fuel tank cooler and you too.

[Scott_]

Something else you may think of doing is to insulate the fuel lines and fuel rail.
I've used some of the plumbing pipe insulation for the fuel rail, like you get at your home improvement store. You can also use it for the fuel lines but it's not as easy as it is split for easy installation.
Ideally for the fuel lines, if you can get some "armaflex" refrigeration pipe insulation, would work best. Yes you would have to remove 1 end of the fuel line to install it, but it would not be split down the middle and will stay put better.

[wmax351]

I actually thought of putting a fuel cooler inline. After having boiling fuel driving through utah (on a naked K).

[Jumpin Jimmy B]

 The fuel pump whine can be caused by a loose or worn fuel pump dampner too.

 IMHO things you need to do. No specific order.

 Treat your ride to some Techron FI cleaner. Also good for the pump.

 Install the johnny blanket

 Install a manual fan switch. With this last one, when it's hot out and you run into traffic you can just turn on the fan. I was stuck in traffic yesterday. 93 degrees and
                                           and very humid. As soon as I come up on a situation like stopped traffic I hit my manual fan switch. I was stop nd go for 12 maybe 15
                                           minutes. The temp gauge never got much past the middle point.

 Also of note. A little gas will make a BIG mark on  the pavement. A tabelspoon of gas will be a dinner plate size mark in about a minute. If the ground is sloped even more so.

[552255]

Just on a preventative maintenance note:  fuel filter need changing?...i change mine on all vehicles fairly often thinking it will extend the pumps' life (if thats possible)?   Maybe you can "tighten" the pump bracket as well to reduce the whine.   

[Sebsi]

Thanks for the replies. For the record, I had about a half tank of gas. The next day I was on the road for about 10 minutes in 85 degree heat and got the spill again, so this bike is really spitting it out.

I dug around a bit and it looks like my problem (and solution) are fairly common:

http://k11og.org/forum/viewtopic.php?t=8157&highlight=fuel+leak

I'll install the submersible hosing when I run the gas down in the tank. Is there a technical term for this kind of hose? is sounds like it's not a standard fuel hose and should be the same type of metal braided material that's already on the fuel hoses in the tank, right?

The fuel line insulation sounds like a good idea as well.

I've already done the fan mod, so I'll start running that more in hotter weather when I'm moving slower. I'd like to install a Johnny Blanket, but can only source a $25 roll of water heater insulation (which leaves a lot left over) or a custom size of what appears to be little more than bubble wrap with very thin foil on both sides. is that kind of material appropriate?

On a side note, I must say that I'm a bit taken aback by BMW's lack of foresight regarding heat on this (these?) bikes. Are they simply not meant to be run in the type of heat we experience in most of the USA during the summer? How could their engineering department not anticipate/detect the fact that raw gas being squirted back in to the crankcase would stall the engine (hence necessitating the air accumulator; this was my first K bike/heat/fuel issue a couple months back) or that heat would cause the return fuel line to squirt case into the fuel vapor line (thus pressing one's air accumulator into overtime service)? This is my first BMW and I'm a bit perplexed by this....that being said, without you guys around these problems would have been pretty damn hard to diagnose, so thanks!

Seb

[Scott_]

Is there a technical term for this kind of hose? is sounds like it's not a standard fuel hose and should be the same type of metal braided material that's already on the fuel hoses in the tank, right?

It's just the standard fuel line that is rated for submersion in fuel. Nothing braided about it. And it won't be under pressure like the other line on the outside of the tank down to the fuel rail.

[Sebsi]

So I got ahold of some submersible gas hose, spent about an hour try to bend the shed biscuit nipple to get some traction on it, and nearly wrenched my hand off (I have big hands) trying to slip the too-small hose on the nipple (which, by the way, is not meant to have a hose on it). Finally was able to slip a hose clamp over the connection, and now the return fuel line drains down at the bottom of the tank instead of right next to the return spray.

The whole thing took a couple of hours and $10 in dealer-supplied parts (hose). I'm looking forward to a blistering hot day tomorrow to test it.

Added: here's a photo of the gas line in the tank:



Thanks for the help everyone.

Seb