96 impala super sport that has a raw fuel smell coming from vents any ideas on 1996 Chevrolet Impala SS

Happens when the fan mototr is running. there are no fuel leaks. it appears to be coming from the evaporative control system. i can't locate the source of the odor anywhere. i know two other owners of b-bodies who have the same issue. just decided to live with it. no odor unless the HVAC fan is running

Asked by for the 1996 Chevrolet Impala SS
The way you discribe it sounds like it could have a slight fuel leak. All it takes is a tiny bit for the HVAC air intake to pick it up and then you smell it inside. Take the vacume hose off at the pressure regulator on the fuel rail and check for wet fuel there. That style fuel injector is not known to leak but there are o ring seals where it seals to fuel rail that can leak. I run my finger on anthing fuel related to pick up any wetness at all. Also check the test port ... it has a schrader valve that can leak. The evap canister is located in right front fender well quite a ways from air intake but you should look at it also.
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need to know more info sorry