Could the timing be off a little?
Could it be the fuel pump seals? The lines empty back into the tank? (That is purely a guess)
I'd eliminate the easy checks first, voltage outputs at various places listed on this thread (battery, back of alternator)...
How is the belt?
Are the any other symptoms?
Has anything else changed?
When was the last time it had a tune up? Plugs, wires, fuel filter...