I am looking at buying a friends Z28 but there's a few issues:

Starts on second try. Slightly sluggish hesitation while starting but once it starts it's fine. I'm told the starter is fairly new and seems to turn over fine.
??

Strange electronic buzzing coming from rear area, hhhmmm??

Thanks for any input

 

How long are you cranking it before trying again? Are you just putting the key in and cranking right away? I always turn key to "on" position and let the fuel pump prime, then when it stops (about 4 seconds) I turn the key over and the motor will fire within 2 seconds.

Buzzing in the rear-> a working fuel pump. You can get out of the car and go to the rear bumper and hear it with engine idling... if thats the humming noise you are reffering too.

 

Check the fuel pressure. Turn key to "run" (don't start). Should reach ~40psi by the time the pump shuts off. Watch the pressure to see how fast it bleeds off. If you lose pressure rapidly, it will extend the starting times. Rapid pressure loss can be the result of a faulty check valve in the fuel pump, faulty fuel pressure regulator, leaky injectors or a leak in the lines. Cycling the key several times before trying to start may help, but that would simply confirm there is a pressure loss problem.

 

If by the electric noise, you mean the electric fuel pump, generally if it's noticable with all sound insulation in place (including the T-Top storage area cover) then that means it should be replaced sometime in the near future before it leaves you stranded or inconvenienced. GM used a similar fuel pump design on the trucks, and they tend to get louder and louder until ultimately they will fail. I would advise you to change out your fuel pump, and it should help with your starting problem as well.

 

If by sluggish you mean it's not turning over crisply, maybe check the battery.