Look very closely and you will see liquid in the tubing. This is the manifold pressure line to the electronic ignition system.
The fluid in this line will prevent the electronic ignition system from correctly sensing the manifold pressure, which is critical to ensure proper ignition timing at various power settings.
These lines should be routed in such a way that they will not collect fluids.
Although the oil is not desirable, it will not affect the sensed pressure
It shouldn’t, I agree, but over time I have see them block the line and if connected to a MP gauge the gauge starts reacting very slowly or doens’t work correctly at all.
Vic