Fuel pouring

[bughut]

New guy here from New Mexico...been a mechanic all my life but recently ran across a problem on one of my 911s. My 75s with fuel injection was running and driving fine. Drove it to my shop..did great, went to pull it inside for an oil change and all of the sudden it stalled and fuel started pouring...not dripping..from the exhaust and all exhaust outlets at the heads?? All injectors can be pulled and laid out still connected, and as soon as the key is turned( not to crank..just run) all six injectors start blasting away at the same time. I have extra vehicles so I wasn't in a panic to troubleshoot it. Now I have the time and was wondering if anyone has run across this problem. I have tons of spares, just don't want to start slamming parts without a rough idea on where to start. I'm leanings towards the pressure regulator...any thoughts??