One of those "aaah crap!" moments...

[dogtired]

Unfortunately I had to ride to Eden (NSW) for all the wrong reasons, had to bury an uncle.
The ride there was without incident, a lot of legal speeds riding just behaving myself.

I had fuelled up at Cann River on the way through, and had enough fuel to get back there, so didn't bother fuelling up at Eden when I left. I had about 120 kms to the next fuel. I had taken off with my choke out, and only noticed it was still out after some 3/4 of an hour the other side of Genoa, quickly pushed it in and started to think how much juice I had used for a while then got involved in the road and scenery and promptly forgot about consumption.

About 15 kms from Cann River something just didn't feel right. Took me a sec to figure out the bike was surging, or "hunting for fuel", after an initial quick scare that the engine might be trying to seize. A lift of the helmet and a good listen with my sphincter puckering, and fingers on the clutch ready to grab it in case it was the motor, nope, motor sounded healthy, all the usual sounds, and no extra ones. All of a sudden it died, dammit, out of fuel. Luckily where it was safe to pull right off the road. Seriously, I was in back of Bumfuk Egypt, no phone reception, no nothing.

Stopped the bike, got off, lit a smoke and started to digest what exactly had happened before I touched anything. Finished the smoke, carefully opened the fuel cap listening for a sucking sound, only to see a lot of fuel still in the tank. Closed the tank, and tried to start it again, dead as a dodo. Now this had me thinking harder, blocked fuel line, crusted up petcock, what the hell else could it be?

Time for another smoke and a think. Did it get a gutful of something, is there an in line fuel filter in this somewhere..? Finished my smoke, and just out of curiosity, I cranked her over, one cylinder fired, I kept it winding with one cylinder firing, a second kicked in, and it started to come back to life, three cylinders, all four firing now, crisp and all healthy. WTF? Get ya helmet on and get on it Denis! Lets go!

Has behaved impeccably since.

Only thing I can think of is an air lock in the fuel cap that somehow cleared itself. But why would it wait near 200 kms before it blocked, and why hasn't it done it since?
Any other suggestions?

[rktmanfj]

What year is your FJ?   

[fintip]

I experienced exactly these symptoms once. I pretty conclusively determined it was the vacuum failing on the petcock; your petcock valve eventually stops 'sealing' when sucked on by the engine, so it only partially opens. This means you slowly use more fuel than your petcock is willing to supply. Eventually, your bowls starve. For mine, it only happened if I was cruising at illegal speeds for several minutes; could happen to you sooner.

Of course, that doesn't apply if you have an '89 or newer, as those come with fuel pumps. If that's the case, then who knows! I feel like you would have mentioned something about the fuel pump, though.

The solution seems to be to just buy a new petcock. Which sucks. They're really expensive. Randy has them. I still haven't done so with mine, isn't an issue when I'm driving like a good boy. I'm still hoping I can devise a homebrew method to re-hab mine.

[Harvy]

What year is your FJ?   

'86 Randy

[FJmonkey]

Here is my saga with a failing vacuum diaphragm, 5 pages and since the Monkey Ranger is involved it has a Happy Ending... 

http://www.fjowners.com/index.php?topic=7484.0