Ok so I have an 07 gti 155se with around 115hrs on it and ever since I've owned it it's had an issue where is sort of hard to start intermittently.

When climb on for the first time in the day it will take 3 or so attempts of cranking before it will finally run.

Once it starts it can be ran all day no issues at all, however if it has been stopped for 3-4 mins then it takes 3 or so atempts to start. Once it has been started it runs great.

Things I've changed
Battery. (Brand new 600amp) tested
Starter
Battery grounds cleaned
Spark plugs

I'm thinking it's gonna be the check valve in the fuel pressure regulator loosing fuel pressure and making it hard to start. Because if it has been under 3 mins it starts right back up

Any advice you can give id appreciate it greatly.

Also I have an 05 RXT fuel pump just sitting here would this fit in the 07 gti 155?