More carb gremlins. fuel leaking into engine.

[scottydont]

Anybody have suggestions for sources of fuel dripping into the engine when the vehicle is off. I just found 1-2 qt of gas in my crankcase.

Carbs are newly rebuilt, and I had them apart yesterday to clean some mysteriously gelled gas out of them, but the problem predates me tearing them down to clean the gunk out.

My best guess right now is gravity siphoning the gas and a leaky float needle, or maybe just a leaky float needle and the gas building up a few ounces at a time... But I couldn't see anything coming out the float bowl vent when I looked. Could it be leaking out of a plug or metering port somewhere?

[Bobby65]

fuel pumps fail and are nutorious for leaking fuel into the crankcase, i would replace the pump and that should take car of the problem

[terribleted]

Faulty fuel pump, float level set too high, or stuck float valve are the primary causes of this type problem.

[scottydont]

Guarantee the fuel pump isnt the problem. I don't have a mechanical pump ;)

[davemotohead]

What do you have and how is it hooked up? I guess in your other thread when I asked you to look down the carb you saw a dribble? Too much fuel presure will cause the floats not to close and will flood your carbs and crankcase with fuel,you only need 2-3 psi fuel presure max,What ya got? start posting pictures of your stuff if you could as someone might spot other problems and be able to better help you out.

[scottydont]

Nope Dave, no dribble. Like I said though, looking down the carbs is tough due to the low overhead in the VW engine compartment.

I've got a low pressure electronic fuel pump mounted below the tank (right in front of the engine) Haven't checked pressure since I don't have a convenient in line gauge, but it might be as high as 5psi. I don't think its a fuel pressure issue though. From what I can tell, the leakage is most likely to be occurring when the engine is sitting. The tank is above the level of the carbs, so a slow leak would just keep flowing and fill the combustion chambers (and crankcase as it leaked past the rings).

Really what I was asking was where in the carbs to look for fuel draining. I understand the potential causes. If I do have a slow leak when the engine is off, I'll just put a fuel shutoff solenoid in line and that will fix the issue. I just want to confirm that the issue is ongoing before I go to the trouble. It could have stopped when I cleaned the carbs out.

As far as photos go, I'm kind of a luddite when it comes to technology. since I can't upload directly to the site from my computer, I usually don't have the patience to go through the extra steps to put them on a photo sharing site first.

[terribleted]

I would bet seeping thru the needle valves. Lower float levels a little perhaps and be sure valves are clean and not binding at all. Fuel shut off would stop it but may not be necessary. There is no passage that I have ever seen leak into the crank case unless the carbs are over full.

[scottydont]

Thanks Ted. I couldn't think of anything but the float bowl vent as the leakage point, unless fuel soaked through the gasket and flowed directly down the throat of the carb, but I didn't see any sign of either.... I'll keep an eye on things but I'm really hoping that cleaning out the carbs has resolved the issue. I may still put a valve in for good measure. Having the tank above the carbs is not exactly an ideal situation.