Adk46

The deluxe approach would be to use hard, plastic, skinny vacuum hose. Pump acetone into it. Don't do it indoors or without insurance. Use a heat gun - carefully - on the return line in the vicinity of the blockage - stuff dissolves much faster when warm. You'll need catch basins at both ends, assuming success.

Won't work if the blockage is rust, of course.

Adamant1971

No luck un-plugging the line. At this point its wasted time/effort if I continue trying to free it up, it's plugged real good. On to replacement.

BIMMERMIKE

Cut the line in a convenient place and try the hard line/pipe snake again.
Once clear you can splice line together.

Mrmerlin

note try a piece of weed whacker line

Adamant1971

jetson8859

I have had luck by fraying the end of the line to give it a little more bite then putting other end in a cordless drill and spinning it while running it up and down in the plugged pipe to clear it.

Good luck! And if successful can thank Kevin_in_Atlanta as he gave me the tip.

Majestic Moose

I have used wire rope in a drill with the ends frayed before to clear out coked up EGR passages on another car. There is not much that could resist that.

Wisconsin Joe

Something that has been known to work with the sunroof drains is to take the end of the weed whacker line, heat it up a bit and form a "spade" or 'scoop' on the end. flattened, but with a pointy tip.
Obviously, nylon won't cut through a hard plug.

The frayed wire rope may be a better choice. I wouldn't use that on the soft sunroof drains, but that's not an issue on the hard fuel lines.

Adamant1971

Using 2.7 mm thick weed whacker line I was able to determine the exact location of the plug. I have at least 10"-12" of plugged line from right behind the rear control arm mounting point to about half way accross the horizontal section above the resonator heat shield. Whatever is there is solid, I can feel the line bitting into it slightly. If I force it more the line will likley break, and turing it with a drill does not work since the plug is deep in the line.

Mrmerlin

hit the outside of the line with a rubber mallet

BYAIC

Adamant1971

Well since almost everything on this car is new and since I just found another area of rust in the hard lines up to the expansion tank. I'm going to replace the hard lines front to back and R&R the expansion tank bits. I got some serioulsy nasty brown fluid out of the lines as well.

Thanks for everyones help. Hopefully in a few weeks once I have parts for the rest of the fuel system she will be purring like a kitten.

Adamant1971

Update:

So it looks like the acetone eventually did it's job on the return line, that combined with fishing a heavy gauge weed wacker line down the hard lines to clear the obstruction. In the end the most horrible brown sludge came out of the return line. I was fearful that some of this may have gotten into the tank so I drained the tank and the fuel was clean as a whistle. So it looks like the crap never got into the tank. The rear portion of the return line was also heavily corroded, so we cut that portion out and did a flare fitting in behind the lower control arm mounting bracket and transitioned to a stainless wrapped hose back to the top of the tank.

Upon further inspection of the expansion tank and supply line we decided to replace all the lines as the feed line was also heavily corroded in behind the plastic cover that conceals the expansion tank valve. So new hard fuel lines from Porsche (except the bastards bent the under body line for shipping so I had to straighten it), expansion tank lines and the shut off valve.

Up front we replaced both dampers even though they tested fine (preventative) and I also re-tested the Bosch FPR with compressed air and it releases at 55psi as it should.

Yesterday I put on the front damper that I just received from Roger, so the fuel system is ready for a pressure test.

But before doing that I ran the JDS spanner on the car. This tool is freaking awesome. I ended up with a fault with the Temp 2 Sensor, that was solved by cleaning the contacts on the plug and sensor. It also diagnosed the fact that I had forgotten to connect the temp sensor on the bottom of the rad. And it confirmed that I have a good signal from the CPS. I then ran the injector test and all seemed well, but since I'm a little OCD I decided to unplug all the injectors and then test one at a time, and sure enough I have one re-manufactured injector that is not firing #7. I moved the plug to #8 and confirmed the wiring is good, so I will need to pull the driver fuel rail to swap that injector or bench test it.

It has been a long road but we are almost at the end. We should be on the road in a week or two to bed in the rings.

Mrmerlin

For that injector spray some PB blaster into the inlet,
then tap the inlet end on a board a few times go easy,
then test it with a power supply to see if its opening.

NOTE this is a common issue with rebuilt injectors they stick ,
hit the end square so you dont bend the flange

Imo000

Hit it with a 9V battery and see if it comes back to life.