Steveo has a good point about the injectors at idle with too much fuel pressure, if you're too rich you might wash your bores down with fuel.

I accidentally started my new L31 engine with it's...

I have a similar combo, L31 long block, ported Vortec heads, Chevrolet Performance Vortec to TBI intake manifold, Headman long tube headers and a small CompCams 252XFI HR-13 cam, 650CFM throttle body...

What cam are you running and whats your intended RPM range?
That's a fair bit of fuel pressure, I'm assuming Dave has set your base tune around that fuel pressure.
The PCM will potentially...