"Howard Beal" fired this volley in news:ls8lkl$ebu$1
@speranza.aioe.org:

Any idea why it only leaks when the engine is running?

Sure. The system slightly pressurizes the tank so that tank vapors are
passed back into the intake system.

Shouldn't BE any leaks; the system is designed to be airtight. If so, it's
probably a sensor/fuel-pickup gasket problem... but it could be a bad seam.
That's something that needs attention NOW!

In the meanwhile, run your tank no more than 1/2 full to prevent the leak.

Lloyd