RS246.com Forum :: The World's #1 Audi R, S and RS Enthusiast Community

Hi,

I've done several small things myself lately like replacing DV's and installing a pressure gauge, and now I want to replace the vacuum line from the fuel pressure regulator to the intake manifold because I'm suspecting a leak there.

Has anyone experience with this? I mean: it's easy to remove the FPR side, but which parts have to be removed to gain access to the intake part and how is it clamped? I can't see it, not even with a light. Where exactly is the other side of the line located?
Will a normal vacuum line be fine instead of the cotton covered factory line, or will it melt?

Thanks for your info.

nobody knows this?

Yep it's a bit of a sod to do but not too taxing compared to some jobs.

I tested and replaced (where necessary) all vacuum lines about 12 months ago when the over zealous mechanics managed to put a split in the FPR vac pipe whilst trying to for it off without undoing the clip.

So the pipe runs behind and below the EGR/Lambda sensor circuit packs at the back of the inlet manifold. It's ends under a metal shelf to which a number of solenoids are mounted. These control vacuum to the airbox and a couple of other vacuum control circuits.

From memory - Y-pipe, maf etc, off, oil breather moved aside, expansion tank has to be moved aside, black auxiliary air pump taken off (pretty easy). unbolt the EGR/Maf sensor boxes, this then allows access to the mounting plate for the vacuum solenoids and the inlet manifold where the pipe joins it.

There's a diagram and some more waffle on the subject on this post.

http://www.rs246.com/index.php?name=PNp ... =oil+inlet

I used new vac pipe - not the cloth covered stuff - it's all fine.

Thank you very much for the explanation wozza, as I expected it's more work than I thought, but I'll give it a shot!

The pipe is cloth coated rubber as it is fuel pipe.

I would not use standard vac pipe. you can get wiff of fuel in there, even though is just on the vac side.


Darren

As far as I know this pipe doesn't have anything to do with 'fuel itself'. It just regulates the pressure the FPR needs to supply by vac and boost.
The standard DV pipes are also cloth coated..., no fuel in there either.

As you both say its nowt to do with direct fuel delivery - other than indirectly - i.e. if the pipe perishes there will be a vacuum leak which will stop the fuel pressure regulator delivering the correct pressure. Fuel is delivered - via the other reinforced fuel lines on the left of the engine which connect to the fuel rail being steel.

The whiff of fuel (and oil from the crankcase vapour recirc) is from the inlet manifold which is also connected to the outside back through the air cleaner etc etc - bearing in mind the manifold is under vacuum its an air leak and air will go into the manifold not out of - and six pistons sucking air, and injectors which default to closed will take care of everything else.

The cloth stuff I could see may protect against abrasion or be reinforced to stop collapse under vacuum - however I've vac tested the non cloth stuff up to 750mmHG of vacuum and didn't see it collapse.

however - it's about 20p difference a meter choice is your own. Good luck watch your knuckles back there!

http://www.draperhandtools.co.uk/68714- ... t-kit.html

Thanks again for the explanation! I replaced the line with the clothed original stuff because a friend of mine had some spare. Vac reading is a bit better now. Also fixed a small boost leak found during my pressure test. Now I'm ready for tuning
I will visit JD Engineering for a custom mapping.