You run power through the grommet in the firewall to the interior fuse box for 1, which is weird as others just use the engine bay box. They have a little cover you can slip over the ECU with only pin 71 punched out to make depinning the dummy plug easy.. Though it's not difficult if you pay...
https://scskunkwerks.com/products/sc-skunkwerks-mqb-mpi-ready-manifold
No issues with the diaphragms so far on these, comes with flap position sensor and vacuum module.
You can do OEM+ MPI for a pretty decent price. Some might say you spent half of what an MPI kit would cost with Manifold, fuel hose, clamps and everything else needed to make it plug and play, on HPFP internals.. Shoot me a PM if interested, I've got my kits ready to go currently and offering a...
What's the coolant look like? Oil cooler seals go and leak oil into the coolant. Normally won't see coolant in the oil with that leak, just oil in or discolored coolant.