Question about a ford 5.4

[KMGZ400]

I have a 2011 ford E350 with a 5.4, 110k miles. I'm having a problem only when I am filling up with fuel. After I fill up with fuel with the engine off, it takes about 15-20 seconds to start, and when it starts it will sputter for 5 seconds then run fine. If you leave it running while filling up the RPMs fluctuate badly and shoots a faint black smoke out of the exhaust then runs fine after you drive it. Again this only happens when filling up. Has a new 5.4 with only about 10k miles on it, don't think that has anything to with it though. Thanks

[Jsdirt]

That's an odd one - sounds like an EVAP valve is stuck wide open allowing fuel or fumes to travel right into the intake manifold.

[KMGZ400]

That's an odd one - sounds like an EVAP valve is stuck wide open allowing fuel or fumes to travel right into the intake manifold.

Yeah from what I'm gathering it's some sort of EVAP issue. Haven't been able to get a consistent answer but just looking for opinions before I throw parts into it

[Doug_Scott]

It pretty much has to be in the EVAP system. Some vehicles are very sensitive to fuel tank "pressures" as well. They usually throw a code though. Are you not getting a CEL? You may want to check for any codes in the history. Sometimes a code will not set the light due to the length of time the component is out of spec. I would record the codes in history, then clear all stored codes and then try to duplicate the issue. You should have a clear view of the codes being set this way without having "junk" codes adding to the confusion.

[KMGZ400]

It pretty much has to be in the EVAP system. Some vehicles are very sensitive to fuel tank "pressures" as well. They usually throw a code though. Are you not getting a CEL? You may want to check for any codes in the history. Sometimes a code will not set the light due to the length of time the component is out of spec. I would record the codes in history, then clear all stored codes and then try to duplicate the issue. You should have a clear view of the codes being set this way without having "junk" codes adding to the confusion.

i have never seen a CEL on and there isnt one on, even when it sputters it still dosent throw a code. i will take a look at the code history