i have a 2007 pacifica touring 4.0 and when i turn on the heat i get a strong odor of gas inside vehicle. i checked the system and no physical leak is detected under pressure or static also no serious drop noted on gauge when vehicle is running does anyone know what can cause this problem

 

I had a problem like that on my 98' Cirrus. Clogged fuel injector was pushing the gas out, streaming down the injector, on to the engine, heated up and the fumes came through the vents. Maybe look there to start off.