Lack of Power Intermittently

Hi guys, in the works of trying to figure this out with a RenaultSpeed in Farnborough but want to hear some opinions on here.

Had this issue for the last 2-3 weeks where the car will intermittently cut power, the turbo won't spool and give me boost, as if it has just been cut. Then all of a sudden, after a gear change or slowing for a junction/roundabout, I'll pull away with full boost again. I've persistently had it like this for 4-5 times I've driven the car, until yesterday, I drove the car 3 hours and it didn't cut power once. Today, issue is back and struggling to get over 2000rpm like before, as the turbo isn't giving any boost.

I don't think it's the turbo itself, as I have full power when the issue intermittently goes away. I've been to Renaultspeed, had it on Renault Click, and NO CODES?? Zero fault codes. Stored or present?? Very strange. Terry at Renaultspeed said the MAF or the air flow sensor doesn't communicate with Renault Click, so could be an issue with that? The car really struggles to start after being sat for more than 12 hours, so could those issues be linked?

He also suggested Fuel pump/fuel pressure issues, but he was sure things of that nature would come up on Renault Click.

I'm loving the drive of the car when its working, but I'm starting to fear this is going to ruin my bank account sorting all these issues.. Any help would be massively appreciated.

I've spoken to Ian Plymouth about the poor starting, and he mentioned crank sensor or TDC sensor, is there any reason to believe these would communicate with Renault Click? I was expecting to see these codes. So kinda stumped now none of these things flagged...

Cheers guys. Any help would be massively appreciated.

 

Update: Had a poke about. So this issue is related to temperature, air flow, and diesel potentially burning too cold…

What is that oil residue on the seal fitting the left to right pipe, on the right hand side? It connects to the pipe leading from the air box to the turbo.. any ideas??