86 Grand Marquis - Gas odor + hesitation

My old '86 grand marquis has a 5.0L EFI with around 300,000 KM on it. And it's been running exceptionaly well for a vehicle with that many miles on it since I bought it back in october, but recently, since its begun to warm up, I've been getting a strong gasoline smell while the car is running (hot or cold) and while it is cold it hesitates at stops. The hesitation goes away after the car has heated up, but the gas smell remains. I was wondering if this in idicative of a bad 02 sensor or mass air flow sensor?

I barely have to touch the ignition and the car fires right up, so I dont think its an ignition issue. Also I've been keeping an eye on the transmission fluid thinking the tranny had started to slip, but the fluid is neither turning dark or has a burnt smell to it. As of yet i have not had the engine light come on, but lord knows that could change anytime now.

So if anyone has any further insights, or needs more information let me know.

BTW i paid all of $500 for this beater and if its anything serious i'm not going to be too worried about it, but if its a cheap fix i can do with a jack in my driveway i'm all for it.

So the smell of gas is coming from where? Under the vehicle? It being an 86 maybe the fuel line or the fuel filter has tiny leak... small enough that the fuel pump can still compensate.

Is the odor coming out of the tail pipe?

Guy at work has an F150 and had to replace all the brake lines, but here in Michigan the counties use salt to melt snow.

It wasn't a smell i could never pinpoint, however the water pump went and the block cracked so now its a cube somewhere, so no worry's!