Okay I have a 1992 camaro z28 305tpi.The car take long cranks or two turn of the key to start.I looked around I change the fuel pump relay wires spark plugs injectors are fine.i can hear the fuel pump turn on and the shut off after a few seconds.i did change the battery and it fix the problem but then it came back.This only happen when cold start or sat for a while but there is a little hesitation when I come back from the store after drivin around for a while please help.

 

When you first turn the key on, the fuel pump should turn on for 2 seconds, then shut off. When you turn the key off, there's a time delay between when it will run for another 2 seconds with the key turned back on. That's normal, so look else where. Check your fuel pressure and do a pressure drop test on the fuel system with the car off.

 

Lets say its a fuel pressure problem what can I do to fix it

 

need to make sure your injectors aren't leaking, if fuel pressure drops pretty quickly after shutoff, thats a likely culprit

 

No injector are not leaking quick question why when I change my battery it fix the problem but in a couple of weeks it came back.Also the acc fuse is blown dose that have anything to do with it

 

You need to do the fuel pressure tests to determine why the rail pressure is not holding.
Could be
a faulty check valve in the tank ,
a a faulty regulator leaking off pressure
or leaking injectors.
All of this assumes you are getting the correct pressure when the pump runs
Only the correct test will determine the problem.

Just because the " pump is running " does not mean you have the right pressure.
Test with a pressure gauge only

 

Okay so I had it check out and it turn out to be the fuel pressure regular but know the oil smell like gas I was told is was because of the fuel pressure regular but my question is do I have to change the oil know

 

If you have gas in your oil, which you probably, then you have to change that oil. Thinner oil means less friction protection.