I have searched and read the various fuel leak threads across all forums and none of them really seem to fit a problem that I have now experienced twice - once on my 1973 911 and most recently on my 1971 911E

after not driving the cars for several months (3 to 6) and leaving them sitting in my air conditioned garage, when I started the car, a significant amount (maybe a quart) of fuel pumped out under the fuel pump - I did not notice this until I drove off and saw/smelled the leak and quickly shut the car down to avoid fire

after a few minutes cleaning up the dumped fuel, I restarted the car... no leak

I have checked the fuel lines and pump connections and found no leakage on the second and subsequent start ups - the problem occurred only once so far on each car - it is not a recurring problem so far

various theories suggested to me seem to revolve around dried seals which take a bit of running to absorb moisture and re seat to seal

any thoughts - anyone with similar problem?

 

First off, Welcome to Rennlist.

Your problem sounds unique an I've also not seen a post on this. Your hunch sounds plausible and worrisome.

Is it possible that the pressure in the fuel system backed up into the charcoal cannister or overflow container and it has a crack or the hoses are cracked or disconnected? boy was that convoluted.

 

I've had the same problem on my '79 911. Two separate times when I've come back from a week vacation and started the car, I get a fuel leak under the car (center underbody of car just in front of back tires). Once I drive it, the problem seems to go away. Having a mechanic look at it to see if he could duplicate problem.

 

I have now had the problem recur (under similar circumstances) -- this time, I was able to check the fuel line quickly and it was wet a few inches down from the fuel pump, so I think it is some form of fuel line failure.... I think I can solve the problem by

- driving my cars more often; but first by
- replacing fuel lines (just not worth the fire risk to hope it doesn't happen again or worse yet with engine at temperature)

 

fuel lines would be such a cheap investment compared to losing a car to fire. Even if you dont drive often good fuel lines should not leak. Glad you found the problem before anything worse happened.

 

actually, after more investigation, the real problem was resolved by simply tightening the fuel filters - in the rear, at the accumulator -- on both leaking cars, the canisters tightened 1/4 to 1/2 turn -- maybe seal shrinkage, but seems to have resolved the issue on both cars....