WTF a young man had posted a thread about a smell of gas with A/C on . i jumped on the thread because i have same problem . i hit the book , service man. ,
[ real chevy , not chilton or haynes ] think i found problem . went to answer , could not find thread . where was it moved to ??? anyway looks like the problem may be removal of the rubber seal on the back of the hood . looks like outside air is drawn in from base of windsheild and we are drawing in eng. fumes . glad i didn't throw mine away , will put it back on in the morning and see what happens . anyone else had this problem ???

I did once but it could have been deltaco too ... J/K

thanks ,your info was a great ,if not super help with the problem . many , many thanks for your input . [ glad i don't have your output in my car ] .

If you have a smell of gas throught the HVAC because the seal is missing, I think I would try to find why the fumes are are under the hood in the first place. Do you have a fuel or exhaust leak?

no leaks just the smell of a warm engine that's been in place for 19 yrs. btw i put seal back on today and no more smell in stop and go .