94' Camry fumes in cabin

I just bought a 94' Toyota Camry. Whenever I drive I notice these fumes, not exhaust fumes but something else like gas. The smell makes me dizzy and sticks to my clothes so I end up smelling like these fumes when Im out and it sucks. My inlaw took a look at it and said the previously guy may have used some engine cleaner which left residue so we let it run with the hood open and the heater on for half an hour, the smell went away a little bit but it still makes me dizzy and stinks up my clothes. We checked the fuel lines, they don seem to be leaking. Any idea of what else to do?

If you are sure it's not exhaust, it could be oil leaking on to a hot exhaust component or even coolant leaking inside the passenger compartment from the heater core. Coolant has a sweet smell to it. Is the smell kind of sweet? It's really hard to tell without a more accurate description of the smell or experiencing it in person.

Mike