Hey everyone. B7 2005.5 A4 2.0T here. Interesting problem here. I have a CEL and I wish now I remember it exactly but it is related to N276 fuel pressure regulator. The only symptom is periodically an average of once a month the car will drop RPMs and die, always at idle or right after putting it into drive. Then I will start it up and have to give it gas and once I rev it high it seems to work although it does at first struggle to rev over 4-5k.

Replaced CAM follower and had it inspected twice within 5k miles of driving before having it replaced as a possible cause. My mechanic said no lobe or cam wear and the pump looked fine but did point out a crack in the push/pull connector on top of the HPFP which is where the n276 valve is if I'm not mistaken. Thought he might have been lazy and didn't really check it before when trying to diagnose my car(he never seemed urgent). Because of this I asked for my old follower back and when I went to get my car it had conveniently been "run over on accident" and was given to me in pieces. But even from the pieces I had it looked like the black coating was worn off at best and and worst that it had a hole in it.

A few days later I'm sitting in the car idle and it dies. I start it back up to no fuel pressure. If i gave it gentle throttle it could accelerate slowly but as soon as I gave it hard throttle the RPMs would go up (not higher than like 5k) but the car would not accelerate. After a day of it sitting I try again, get mad, bang on the HPFP a little and BAM it works. I drive it like this for weeks, no issue.

Replace the HPFP last night. Still getting n276 code. Car idle dips and dies at drive thru CVS. I get it instantly running again with 0 issue and drive it home.

Any insight would be great. Maybe despite 2 mechanics telling me the lobe and cam look good it is worn? The return spring on my old HPFP is worn and looks as though it was rubbing somewhere.

Other useful facts; Its on 05.5 and has an older BPY engine so probably a revision A cam; It also has a loose vac hose from the camshaft to the break booster. Idk if this would cause issues. Doubtful.

If it is the camshaft, what exact parts do I need to replace? Thanks for any insight anyone may have

 

I'm no expert, but just comparing yours to what mine looked like about 18 months ago (Audi service tech sent me the picture--I didn't see it in person), yours appears pretty worn. If your HPFP wore that badly, I would imagine your cam lobe is worn as well and probably causing your issues.



The loose fitting between the brake vacuum pump and the brake booster is a common issue and requires a new vacuum pump to fix it. I just had mine replaced. The part alone is around $260. It is not related to your CEL, codes, or stalling issue. All that will cause is some oil blow and a harder than normal brake pedal because you're leaking vacuum.