1991 Audi Coupe Quattro Fuel Line Woes
On the 2200 mile trip back from Chicago, we had a hard time exceeding 20 mpg on the freeway, and on the second day we started smelling gas....
On a lift it was easy to see the source of the smell - here it is, about four
inches from a smoking hot catalytic converter. We were lucky indeed that we did
not burn to a crisp!
The heat shield peeled back, revealing the leak. The inboard line is the
pressure line to the injectors. I strongly
urge ALL Coupe Quattro owners to inspect this area closely!
The kind and sympathetic mechanic stopped the leak temporarily so we could get
the rest of the way home.
The rusted lines lying on my garage floor. At just
about every rubber clamp the lines were rusty.
Close-up.
More rust.
I used 5/16 inch stainless tubing with SAE flared couplings to connect to the
undamaged lines at the cat. My local hose shop bent them to match the old ones,
but unfortunately rusted parts fell off two old lines on the way to the
workbench, and two new lines were too short, so I had to add small sections to
span the gaps.
I single flared the cut ends of the old OEM lines after slipping new sleeves over them. Access was tight but not too difficult....
The new lines are a slightly larger OD than the old, and they were difficult to get into the OEM rubber mounts. I ended up tossing those rubbers. I used a grinder to shorted the threaded studs that hold the steel clips to the body. I then closed the clips around the new lines and slid sliced 5/16 inch ID fuel hose over each one. When all three were in place, I injected the gaps with silicone sealant to keep everything tight and secure. The mounts look a bit flakey but they are secure and safe.
New lines at the back, with a new filter.
Another view looking forward from near the center muffler.
I removed the fuel pump relay and jumpered 12 volt battery power to Terminal 52
in the relay box (as shown in this scan from the Maintenance Manual page 20.23).
I corrected a couple of fuel leaks and let the pump run for about 30 minutes to
make sure the system was tight and leak free.
This is not a job for the faint hearted, but it isn't too difficult for those skilled at pipe bending and flaring.
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New Oct 02, 2009 |