smell gas and Car wouldn't start until 3rd try

[Cobra Jet R]

Hi all, newbie here. Have never had a problem with the car before until today. It has 105K and has been great but this past week I've been smelling gas around the car and this morning I started it up and it cut off. Then I waited a few minutes and it started but was idling rough and shaking a bit and little bit of smoke came out of the pipes for a second then it ran fine the rest of the day.
It has no motor mods and I got the oil and plugs changed about a month ago. Anyone know what it could be? There's also a hissing sound coming fromthe motor when I start it up but eventually goes away. That's been going on for a few months. THanks

 

[SinisterSTANG]

I would replace the fuel filter and check the fuel lines and injectors for any leaks as well as the fuel filler neck grommet on the tank. I had a gas leak due to the grommet being ripped and just replaced it. Are you getting a Check Engine Light? The hissing sound could be anything, belt possibly, hard to tell without hearing where it's coming from.

 

[Red98CobraStang]

I'm guna go out on a limb here and say a possible FPR?

just as a routinr maintence kind of thing, replace air filter, clean IAC and MAF, change fuel filter.

 

[doubletrouble]

I too say Fuel Pressure Regulater (FPR).

 

[Cobra Jet R]

I don't get a check engine light. I did also have the fuel filter replaced with plugs and oil but forgot to mention it. Air cleaner is K&N and I cleaned a few thousand miles ago. Will check FPR. I've never had the Fuel Injectors cleaned. Do you think that's something I should do or maybe get an injector cleaner additive? If it is the FPR, should I look for a specific one if I plan on rebuilding motor and adding ~7-8lbs boost via a blower? Thanks guys.