I'm trying to diagnose an issue my sister has been having on her 2010 with the V6. Dealer can't find anything wrong with it

She says when she stops to get gas, it has trouble starting back. Will crank, but not start. has to try it several times. Sometimes pumping gas will help. (Sounds maybe like IAC to me)
She says when she's driving, that sometimes it will quit. Best I can understand from her description, it's when she's off the throttle. She says most of the time it will start right back up then.
She also says sometimes when she's trying to crank it back, it acts almost like a bad starter, or battery. Starter getting slower, then speeding back up.
Also says that sometimes it acts like it's low on power. She has to floor it to make it go.

Any suggestions? My thoughts are IAC or faulty fuel pump?

 

No pre-codes? I would think there should be some.....

 

Nothing is showing up they tell her. I would have thought there would be some codes as well...

 

Try a different dealer, possibly even a parts store to read the codes, I wouldn't believe there are simply <none>

 

I think there was a recall a few yours ago for the throttle body.If its gummed up or something like that it might not open and close the throttle blade fast enough to adjust for driving If it has a Iac valve. When mine on my 01 went it was hard to start when hot. When running no issues. Also no codes.

 

I think I would be looking at the 'drive by wire' stuff if it has that feature. Depending on vintage, there may be no throttle linkage or cable connecting the gas pedal to the throttle body. I do not remember what year it changed.
The computer is controlling the engine rpm, and seems to be failing, in human viewpoint, but it might be doing exactly what the computer commanded in its view.
I think there was a recall on the electric throttle bodies, but don't bet the paycheck.
If no codes, I'd at least remove, inspect and possibly clean the throttle body and plate.
If it does have an IAC, I would be cleaning that, and checking the wires and connectors for damage, corrosion, or looseness.
Does the 'change' in operation happen slowly, over time, or all of a sudden? The latter points more toward an electrical problem, the former something else, such as a fuel flow problem that is somewhat covered by the reservoir effect of the fuel line.
tom