Replace Fuel Pressure Regulator (FPR) and Hose, 1.8T VW and Audi DIY
Replacing FPR Hose and FPR
The braided hose that is connected to the fuel pressure regulator (FPR) is a common spot for vacuum leaks on 1.8t's. It dries out and rots easily causing your car to have a bad idle due to the leaking hose. Your FPR can also get clogged and stuck from previous owners using low quality gas. The odds of your FPR actually going bad are pretty low, but if you do feel the need to change it out or pull it out so you can polish it, then this DIY is for you.
This DIY is very easy and the only tool you will need is a flathead screwdriver. You will also need zipties/hose clamps, and replacement hose.
For the FPR hose replacement you can use "fuel line" that should cost a few dollars at an auto shop (Pep Boys sells it by the foot). You can also buy silicone hose online in many different colors to use as a replacement. When buying silicone hose make sure it is heat treated. I learned my lesson when I bought a silicone hose kit made by Spectra at Autozone. Within 50 miles the hoses had melted together, whereas my other silicone hoses have been fine for over 50 thousand miles.
This hose is about six inches long, It runs from the fuel pressure regulator to a small port under the intake manifold. The hardest part about this diy is getting the new hose and clamp back on the intake manifold.
The hose has metal clamps on both sides, don't let that scare you. Even with the metal crimp clamps on, you should still be able to pull the hose off with a little force. If not you can grab the crimp of the clamp with some pliers and move it back and forth to loosen it enough to pull it off.
Once the hose is off the replacement it is as simple as cutting your new hose to its proper length and re-installing. You can use zipties or small hose clamps. I personally like zipties because they are cheap, you can tighten them as good as a hose clamp, and they won't cut the silicone.
Removing the Fuel Pressure Regulator
If you choose to remove the FPR, whether it be to put in a 4 bar, replace it, or just give your old one a nice polish to match your nicely polished intake manifold then this part is for you.
Once you have removed the hose from the FPR the next step would be pulling out the clip that is holding it in (hi-lighted in pink in the picture). Just grip the clip with some needle nose pliers and give it a strong pull. It is metal and will not break, just make sure you pull it out and not up. Once it slides out set it to the side and don't lose the clip.
To pull the FPR out it's a struggle to say the least. The best advise to get it out is to keep turning it in one direction and wiggling it side to side till it pops out. It may seem like a hopeless cause but it will come out. Once it pops out don't be scared with the splash of gas that comes with it.
Once you polish or replace it, putting it back in can be a tight fit. When I say tight, it is like an elephant screwing a puggle. The best way that I've found to fully get it in is get the new one settled and as far down as you can with your hand. (don't forget to lube the o-rings with a little oil).
9. With the o-ring lubed up place a block of wood on top of it and slam your fist down on it once or twice. It should pop it in nice and easy so you can slide the clip back on. Some other DIY's recommend using the handle side of a screwdriver to get it back it but that will leave the top with little round dents.