WhiteThunderZ28

It might be a leaky fuel injector/s flooding out your cylinder/s.

To check your injectors:
- Unbolt you fuel rail
- Remove the injectors from the intake manifold but make sure it is still attached to the fuel rail
-Have the injectors sitting high enough to where you can see the bottom of the fuel injectors
-Turn your car to "ON" but do not start it, you want the fuel system to prime
-Now go and check the injectors leaving the ignition to "ON" and go see if there is any leaking fuel

I did this thinking my injectors were leaking but they weren't. It ended up being my FPR that leaked fuel into the vacuum line and was getting sucked up into the intake resulting in hard starts and poor performance. I ended up changing the injectors to LS1's anyways.

2QUIK6

A leaky inj would also cause the fp to drop when key is off which mine is holding pressure fine. I actually am picking up the car today. Multiple issues found, including the thread locker used in the opti had gotten some of it slung around and on the contacts even though it sat for a day or more after install, coil was weak even the spare which i thought was good was weak but ohmed out ok, and i had a bad ground.