Hey everyone,
I'm stumped. I can't find anything online about this specific issue and it seems like Google just wants to show all those worthless clickbait sites like youfix and others.

Here's the deal:
2012 A7 3.0 supercharged. 7Xk miles, came by for a valve body replacement since it was said to be shifting bad and the Audi dealer said that was the issue. Dealer also said it wasn't starting because of a bad high pressure fuel pump. I'm just doing this to help a friend's family member, btw. So the owner thought it wasn't starting because it needed transmission work... Wrong. I tow it into my garage and put the valve body in, prefill, all that and then move to the no-start issue. It has codes for low rail pressure, extended start time, and the P0091 for fuel pressure regulator control circuit A low. In my studying, that could be HPFP (high pressure pump) or it could be the pressure regulator on the low pressure pump assembly. I checked in the car and I saw a box for a new OEM high pressure pump and I can see it was just installed when I pop the hood. I try starting, and it runs the starter until I disconnect the battery. I pull the plugs and they are fuel fouled. Replace the plugs, install a brand new low pressure (in tank) pump assembly and still the same issue, no change at all. The extra annoying thing is that I'm getting the P0091 code without even starting the car. I can clear it, it goes away, and then I check for codes a 3rd time and its back without even touching the ignition.

Any ideas? I'm going to tow it out of here in 2 days if it isn't running on it's own but I'd like to throw the hail mary out and try the forums before I throw in the towel.

Also, I've tried activating the fuel pump with my Autel scanner and it just says request out of range. Worthless.

 

Update 1:
another shop installed the new high pressure fuel pump WITHOUT the cam follower... Nice. So the camshaft has some scoring from the pump riding directly on it but it seems ok. The car was able to start after a relay was bypassed and now the remaining issue is to find the reason for the relay to not be energized. Halfway there!