In my opinion you should fix one stuff at a time. I wouldn't remove the intake manifold just yet until you've fixed the vehicle hard to start.
1) Where is the gunk you're describing and where do you think it's coming from? If the gunk you're describing is under the intake manifold, it is probably oil leaking through the swirl flap seals, not fuel.
2) Are there bubbles in the fuel lines before you start the car? Check every hose, specially the one on top of the fuel filter. Replace hose orings.
3) Does the starter motor crank? For how long until the engine starts?
4) Can you see air in the fuel hoses once the car has started?
As I already said, your filter is not right for this vehicle, I don't know which technician did it but he didn't do a good job. I would start by placing the correct fuel filter, MAHLE ORIGINAL KL 188 is OEM spec and I confirm it works on this vehicle.
- The bent pipe is the entry point from the fuel tank.
- The hole in the middle is the output point to the low pressure fuel pump
- The other hole with the two brackets is the return point from the common rail. There is a valve that fits there (A6110780249), my understanding is the valve returns the diesel to the fuel filter until a certain temperature has been archieved, after that it returns the diesel to the fuel tank.
- The plug is a bleed plug.
- There's a plug at the side/bottom of the filter, that's for removing water in case of WIF light ON.
- There's a hole at the bottom of the filter to fit the water in fuel sensor.
Be sure to replace ALL orings in the fuel filter by NEW ones if the new fuel filter doesn't come with new ones.
Once you have the new fuel filter installed, follow the steps to prime it:
https://www.ausjeepoffroad.com/forum...26#post1694326
PS: or I could be completely wrong and you guys in Australia got a completely different kind of filter.