Saturn Aura XR, excessive crank

[Shawn]

I own a 2007 Saturn Aura XR that has 171K total miles on it. I've had it since the summer of 2009 and I've driven it approximately 140K miles. The following problem has plagued me for approximately the last 12 months: Whenever I fill the gas tank, the very next time I try to start the car it doesn't start right up like it usually does but "cranks" quite excessively. After a few tries it finally starts up. To put it concisely -

- car is low on fuel
- engine is turned off
- tank is filled
- attempt to start engine, fails, resulting in abnormal amount of cranking
- 2 or 3 subsequent start attempts are usually needed to start

I've paid quite close attention to the behavioral of the car the past several months. Usually it starts right up with no hesitation whatsoever. The only time it gives me trouble is when I top off the fuel tank, NO OTHER TIME. Seriously, it has never, not once, given me a hard time starting except for when I top it off with fuel. Anyone have any thoughts on what might be going on?

[Geoff Welsh]

my thought is that there is something wrong with the vapor recovery
system, which /should/ be setting a check engine light, and that you are
unknowingly slightly over-filling the gas tank, and flooding the intake
manifold with gas. Start watching the gallon-meter at the fuel station
and stop filling BEFORE the station pump clicks, as a step-one troubleshoot.

GW

[Shawn]

Ah, very interesting. Thanks so much for your insight. Actually, my check engine light has been illuminated for months. I had the car checked out when I first noticed the light and the tech told me that an "evap. leak" was causing the light. The tech looked and looked but couldn't find a leak in the fuel system.

Here's a silly question. . . If there is something wrong with the vapor recovery system, can this lead to decreased fuel economy? Thanks again!

[Geoff Welsh]

only a little. Sounds like you already have your answer to the problem.
Fix the evap leak. I'd guess the purge valve is likely leaking, so
you are overfilling the tank, and flooding the engine.
GW