My fuel system is it enough?

rovert

You need to get a fuel pressure gauge on it that you can read from in the car or on a dyno.
If fuel pressure drops off when the issue arises you'll know your looking in the right place.
If not, you can start to look elsewhere (injectors etc.)
If the stock pump is only feeding the walbro it should be fine in regard to current draw & fuel flow. Thats not to say its not the problem though, as it may be past its "use by".

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08 Skyline 370GT SP Coupe 5AT: Diy TT