Hard start ups with erratic idle

[Wizeguy]

Hey guys,
My cousin just bought a 95 Stang with a 302, a bunch of mods were done from the block being punched 30 over to bigger fuel injectors..Question is when you turn the car off and try to start it back up (hot or cold),
1. Engine just cranks
2. Once it does start, it has an erratic idle for about 20 seconds then smoothes out and then car runs strong,
3. smells like gas!.
As far as I know it has the original computer in it with no modification done to it. BTW the check engine light is not on.
Any idea what this could be? OR any recommendation on where to take it?
I did get a recommendation on a place off of Groesbeck S. of Cass.

 

[BigWheelinBubba]

Possibly the fuel pump relay.

Open the gas cap and listen in the tank for the pump to prime while someone turns on the key without starting the car. It should prime for 2 secondds or so. If it doesn't the relay or the pump itself may be going bad.

Also check around the injectors for leaking o-rings.

 

[MentallyChallenged]

I have very similar issues with a 5.0 that has leaking head gaskets. That's hard to pin down. Is the mass air meter calibrated for the injectors? and how big is the cam? This could be an expensive thing to fix if not done yourself.