Recently I replaced the oil injection lines with small-engine fuel line. (All I had access to at the time and it will last until I rebuild the engine.)

Because the lines were empty, I've been premixing (albiet a bit much, but my first time) until they filled. However, one of them is not filling, the #1. Now, could this be a bit of grit caught in one of the bolts/banjo fittings preventing oil getting through? Or perhaps, the vac line for that injector is not properly secure? It's not leaking at the lower banjo.

Looking for ideas before I have to remove and examine the pump. Aaron Cake says the pumps don't fail, so methinks it's something else.

 

Seems like I've read that the S5 electronic OMP have experienced failures, and the S4 OMP pumps which are mechanical are less likely to fail.

I wouldn't want to debate this issue with Aaron as he knows more about these cars than I'll probably ever learn.

 

check the vaccum line make sure its secure and hasnt been pulled off

 

So the oil is drawn-up via vac pressure and the pump isn't so much a pump but a metering valve?

 

check the injector itself? did you do what it said on the handbook and blow through it?