P0087 Help

[A4B7Owner]

Greetings,
I have a 2008 A4/B7 M/T with 148k miles and recently had the CEL come on and lost most all acceleration power to the car. After searching the forums and receiving a lot of great information, I pulled the HPFP and found the cam follower had a hole in it. We checked the cam and we could not detect any wear or scratches. We replaced the cam follower and put the pump back in and used VCDS to clear the codes. We drove the car, but it still has no power. The only code we now have is the P0087. I used the VCDS and checked the specified and actual fuel rail pressure. The specified went up and down with acceleration, the actual never changed. It stayed at 7 no matter what. It seems that would point to the HPFP since the actual never changes? It would seem if it were trying to work, the pressure would fluctuate a little, unless the rail sensor is bad? Any other possibilities you could suggest before we invest in a pump?

[Gowking]

How worn was the end of the pump where it seats into the cam follower?

[Theiceman]

If the in tank can't supply supply enough fuel to to hpfp it won't make power.


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[A4B7Owner]

It didn't look like it was too worn, but we will pull the pump again and look more closely at it. Thank you.

[A4B7Owner]

There wasn't any issue on the supply side before the problem with the cam follower. I know that doesn't mean there isn't now though. We can put a pressure gauge on it to test. I was just focused on the fact that the actual pressure never fluctuated and was thinking it more pointed to the pump or the rail sensor, but I have no experience with the a4 and fuel system so was looking for thoughts from others. Thank you.

[Theiceman]

Many cars are driving around with worn through pump followers, I think it's a red herring that is side tracking you.

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[A4B7Owner]

I tested the fuel pressure at the Schrader valve and it was 80psi at idle and while driving. I removed the HPFP, inspected and saw no visible signs of wear. I was able to compress the spring with no issues, so it didn't seem frozen. I verified the cam follower looked good. (it is new). I reassembled and tested and fuel rail actual pressure remains at 7.00 idle and driving. When the vehicle turns off, the rail pressure actual immediately begins to climb as it should. It seems like it is either cam or hpfp at this point, but open for suggestions... I was thinking if it was the cam, I would see fluctuations in the actual pressure. Is there any way to verify the cam is ok? Would it be ok to remove the HPFP and verify the cam follower moves as the engine cranks? Of course I don't know what the specs are for how far it should move. I appreciate any suggestions as I try to diagnose this. Thank you

[Jayz691]

You can chexk the wear on the cam lobe. Can use a dial indicator gauge, to check lift. Or pull the cam chain cover, and measure the lobe with a measuring caliper. Here's specs for the tri-lobe.261057

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[A4B7Owner]

Thank you for all the suggestions so far! I pulled the hpfp today and turned the engine and the cam follower did not move at all. I don't see any visible issues with the cam but I have not pulled everything apart to look at it yet and measure it. In looking at the cam follower, when I install it, it only goes so far and stops. It is about 1/8"- 1/4" out of the hole so it can easily be pulled out with pliers. Should it sit flush (if the cam is positioned between the lobes) or should it be out a ways like mine is? Thank you.

[A4B7Owner]

262344
Hopefully if I did this right, there is a picture of my cam follower. It is seated as far in as it will go. I have confirmed that the lobes are at their lowest point. When the cam turns the cam follower doesn't move. I am trying to determine if the cam follower isn't going in far enough, or if the cam was just worn down and needs replacement. The various videos I have watched seem to indicate the cam follower goes in much further, but I can't tell for sure and I don't feel / see anything keeping mine from seating any more. Any guidance would be appreciated. Thank you

[Jayz691]

262344
Hopefully if I did this right, there is a picture of my cam follower. It is seated as far in as it will go. I have confirmed that the lobes are at their lowest point. When the cam turns the cam follower doesn't move. I am trying to determine if the cam follower isn't going in far enough, or if the cam was just worn down and needs replacement. The various videos I have watched seem to indicate the cam follower goes in much further, but I can't tell for sure and I don't feel / see anything keeping mine from seating any more. Any guidance would be appreciated. Thank youYes, it should go in much farther. Get a new follower(INA), just to be sure. Check the bore for any debris. Have you removed the follower to look at the cam?

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[A4B7Owner]

Thank you everyone for your help on this issue. It is solved. Issue was the timing chain cover port was not letting the cam follower seat properly. This caused all the issues. We removed the cover and were able to smooth out the surface to resolve the problem. The issue was very apparent when I removed the cover. We fixed it so the follower now moves freely and seats properly. Reassembled everything and working great. The cam did not appear to have any issues, nor the HPFP.