[landrovered]

Well the immobilizer error code may be more important than you are currently ranking it in your troubleshooting.

Start sequence (not porsche specific) is pretty simple.

Power, ignition switch, inertia switch, immobilizer, fuel pump fuse, fuel pump relay, fuel pump, MAF reading, fuel temperature sensor, coolant temp sensor, throttle position sensor, crank postion sensor, cam position sensor, energize coil packs, starter motor, start.

I have seen where folks suggest starting without the MAF connected, I for one don't think this is a great idea or that it proves anything other than the fact that the ECU has a "limp home mode" fuel curve and will in fact run without a MAF although it runs badly.

The devil is in the details, I suggest you re-examine every one of your "givens" and reconfirm your current assumptions before proceeding further to other systems.

I think I saw that car in the pic for sale on eBay!