im having trouble starting my 02 z28 i takes a few seconds to start after it been sitting it has 100k miles but when the engines warmes up it starts jus fine a friend told me it prob the fuel filter or a dirty throttle body i jus wanna get some opinions first before i do anything but the fuel filters prob never been changed anyways

The next time you let it sit, turn the key to koeo and let the pump fully prime before you start it, see if that helps. A fuel filter is routine maintenance, if you haven't done it before, then it's way overdue. At 100k I would also suggest a tune up.

If you can get a fuel pressure gauge, you could hook it up to the Schrader valve and see what the fuel pressure is doing when this is happening.