Nissan Repair: 2001 Sentra SE stalls after fill-up, air flow meter, fuel cell powers

Question
QUESTION: 2001 Sentra SE will stall after fill-up (regardless of number of gallons) unless I keep it above 1500 rpm for 30 seconds.  Then runs fine.

This may be a complicated issue that started over one year ago and ended when Nissan refunding my cost for repairs that they were not able to fix.  History (parts were changed every time the light came on): The check engine light came on for an EVAP code (there were so many codes over the past year, but they were all evap related).  Initially they changed the ECM, then the valve assembly, then a few wires were replaced/rerouted in the wire harness, then the carbon canister, air flow meter, fuel cell from gas cap to fuel tank (complete), then the ECM (again)….

Eventually the main problem went away, but after they changed the fuel cell I started to have another problem when I filled up (never happen prior to this).  If I put in ½ gal or 10 gals, the car stalls initially, unless I keep it above 1500 rpms for 30 to 40 seconds (kind of building up pressure?).  This is the current problem and they were not able to determine why this was happening; only that it was (clearly).  Now I don’t know what to do.

ANSWER: Hi Rob -

Wow, never heard that one before -

Would you please try this test? Remove the fuel cap, try starting the engine, and see if you have the same trouble?

Let me know -
Aloha
calvin

---------- FOLLOW-UP ----------

QUESTION: I did that and it did not stall.  I also tried to put the gas nozzle in without adding any gas.  Also no problem.  I have to add some gas in order for it to stall.

ANSWER: Hi Rob -

Looks like it may have something to do with the fuel cell that was just replaced. Unfortunately I do not know much about fuel cells, only that it provides electrical power using fuel from an external source. Depending on what the fuel cell powers in your car, it could be affecting the "cold loop", or warm up stages of your engine, and only when you put fuel in the tank.

I would take the car back to where you replaced the fuel cell, or even call them and get their opinion, as it appears the replacement of that cell is causing this problem of yours.

Hope this helps -
aloha
calvin

---------- FOLLOW-UP ----------

QUESTION: The dealership has washed there hands of this issue ( they refunded all my money).

Today I also notices that when I open the gas cap there is no noise (my other car makes a swooshing noise, like a depressurization), I think it used to make that noise as well.  Also I tried filling up with the engine running, it stalled within a few second of adding the gas.  Does any of this help with the diagnostic?

Answer
Hi Rob -

Have you checked the fuel vent line? In fact check all the hoses coming from the fuel tank to the engine. The car is 8 years old, and there just might be some hose that is disconnected (perhaps from the installation of the fuel cell), broken, or cracked. There is the main fuel line that takes fuel to the injector rail, and a few vent lines, one of them goes to the filler neck. Perhaps one of those is your culprit.

I still say there is a good chance it has to do with the installation of the fuel cell, so concentrate on that concept.

I am sorry i cannot be more specific, but please understand that it is difficult to diagnose without physically being there. Especialy a problem like this where you need to poke around.

Hope this helps -
Let me know how this goes -
aloha
calvin