I have quite often a starting problem with my porsche 997 turbo.
When turning the ignition key the first time, the car doesn't start. The battery is new and is certainly not the problem. But when I try a second time, it fires immediately.

Also there is an oscillating rpm immediately after starting and a rough idling thereafter (or even when driving at the same speed).

I suspected a faulty crankshaft sensor, but maybe someone has had the same problem and can help me identifying the problem for sure.

A video tells sometimes more then words. Here you can find 3 video's I recorded.

Thats the fuel pump or at least in my case .

Did you end up replacing the fuel pump? Did you have to replace two on the TT or one? Do you recall how much parts and labor were?

That's definitely fuel related issue. How long is the car sitting when you experience this? What about when warm? Same symptoms?

It depends. When the car isn't used for some days, I notice this problem. But when I shut of the car and try to start it again after 5 minutes it also happens.
Very strange, but it can be the fuel pump of course.

Worth checking your MAF sensors and codes ...

I will check my maf sensors.
I have an obd2 and there were no fault codes..

Clean your MAF. I had the same trouble. MAF cleaner and some q-tips will save you lots of money. A new airfilter would make sense after cleaning.

Easy check, remove the cable from both MAF and start the cold engine. You will see.

for christ sake.

no q-tips. Don't touch the maf sensor wires. Just spray it off with Maf cleaner.