Sorry I have no suggestions but WOW! What an adventure, after all these years!!! I am very happy for you! What a discovery! Congratulations for this excellent troubleshooting! I'm sure it will help others...

 

Thanks @JSBear and @jpflip, the difficult part of this endeavor is there are no throwing codes at all.
It is indeed a very long frustrated and at the same time very self-satisfying ride in figuring out this problem and I'm sure hope this will help other members with similar problems.
With regard to the two methods of fixing, I'm very undecided on which one to choose.
On the one hand I can see the most efficient, effective and forward thinking way is to cut the hole (one hour job start to finish), at the same time provide an access point to be able to replace the ORVR valve in the future in case it is going bad (the engineering thinking cap).
On the other hand, my car is all bone stock in excellent condition with only 21,000+ miles. I would hate to cut (modify) an excellent sample of the first year 2001 water cooled 996 TT (the preservative thinking cap).
Decisions...
Anyone please chime in helping me with the pros and cons between the two repaired methods that I may have overlooked.
Thanks
BV

 

I'm sure you saw the hole on this thread ;-( https://rennlist.com/forums/996-turb...king-fuel.html

 

I was afraid you may say you had a low miles example. If you have the means, and you look at your car as an investment, then maybe you should go the more expensive route. I assume if you were to cut the hole, you would feel obligated to inform the buyer. I assume if the buyer was looking for an investment grade car, that could be a deal breaker. To anyone else, with a nice cap / cover, it's not a huge deal.

Sucks to be in this position, but your response, leads me to believe you may want to go with the "by the book" repair.

I have 35k, mild mods, nothing I couldn't reverse. I would be on the fence a bit too, but initial thoughts would be to lean towards the hole option, with 35k I see my car just outside of the investment grade car, more of a low miles example with light tastful mods. I have most of the stock parts, but not all.

Good luck with your decision.

 

Yes @jpflip that was the post I read about a few month back.
@JSBear I'm still trying to figure out how to solve this problem. I think the problem is the hole is too small to try to slip through the connection after un-snapped the wire connection and fish out the broken wire. I'm very familiar with this type of connection because recently I was able to reconnect the same connection on the engine for the knock sensor on bank 1 and 3 without dropping the engine. I'll need to spend more time trying to retrieve it first before decide what to do next.
Picture of new fuel tank vent valve which I may not needed after all and an old picture of the connection to the knock sensor of the same type of connector.

 

Yes I agreed. But too bad in my case which was diagnosed to be the problem is at the hardest location to reach, the fuel tank vent valve electrical connection which is above the tank and under the CD changer (see my picture on this thread #74).
At this point I'm about 80% decided to cut a hole at that location to fix the problem.
The reason I've almost concluded to fix it this way is because when looking around the front trunk, I notice that Porsche do have various holes at the bottom of the trunk (see picture below) and these were capped using some sort of soft glues around the holes. Porsche should have provide the same hole to access to the fuel tank vent valve in case it went bad.
By the way anybody have any suggestion of the tool to use to cut out a round 3-in thin layer of aluminum (approximately less 1/16 in).
Also if anyone can provide me the type of adhesive Porsche use at those locations indicated by the arrows I would very much appreciated.
I would like to source everything needed prior to starting the repair.
Thank You
BV

 

Maybe something like this? This isn't quite 3", but close, maybe someone makes a 3" version. I'm not sure how much clearance you have underneath, so obviously that has to be taken into consideration.

 

Thanks for your response @JSBear.
That big drill bit would not work for what I plan to do which is to preserve the cut off aluminum and turn it into a cap and refit the hole. It is just like Porsche does at the bottom of the trunk showing in the picture above.
I'm thinking of using a Dremel cut off wheel and carefully/slowly cut a 3-in pre-drawn circle at the location. I think that would work. I'm still searching for the compound Porsche use to mount the plate.
Thanks
BV

 

Any update? Just curious.

 

Hi JSBear,
After do more research on the internet trying to figure out what compound Porsche use to seal their own cut holes as showing in the pictures above, now I have second thought about cutting a hole in a perfect low mileage 2001 996 Turbo. Through my internet search, I have seen many example of high quality restoration shops go through painstakingly process of metal fabrication works to restore Porsche to it original state (for example down to the seams and the number of spot welders suppose to be there at a particular location that was rusted out). These video that I watched make me feel very hesitant on the border of feeling guilty to cut a big hole on the car just to short cut my repair.
Last week, I talk to an independent Porsche repaired mechanic to get an estimate of the cost for the labor of dropping the gas tank to do the repair. I suppose to get back the estimate this week due to the long weekend holiday.
If the estimate is too much, I may decide to do it myself. Meanwhile, I start researching information on how to drop the gas tank to do the repair.
The decision has been made. "No more short cut by cutting the hole".
I will post the progress of my journey.
BV

 

This post is to conclude my journey of figured out and resolved my fuel filling problem.
As the title indicated, I decided to cut the hole instead of spending at least a few days to drop the tank to reconnect the wires and reinstall everything.
What I was concerned were that if I drop the suspension and the fuel tank, I may encounter problems along the way to open or put it back together and therefore went with the safer method.
Here is what I did.
1. Cover the front trunk and tape around the area to be cut. Using a 4-in hole saw arbor kit and a power drill, drilled the hole slowly to preserve the aluminum piece.

2. After opened up the hole, you can see the fuel tank vent valve (996-605-203-01) right under and cover by a grey styrofoam.
For my problem, the CCTV that I did identified broken wires that need to be reconnected, with the help of curve plier (it took some time) I was able to unplug the wiring connection (a little challenging because it is all the against the wall way inside to the left looking from the front of the car). You can see clearly the wiring have been chewed up by mouses.

3. Reconnect all wires and drive to a gas station to check if this is indeed the problem.
!!! Gas flow in and no more pump kick back and spill gasoline all over the filler neck.
4. I cut a 4.5 in black plastic that I have and glue it to the back of the aluminum piece that was cut off. This would allow 1/2 inch under as a base to glue it back to the car.
Make sure that the plastic is a little flexible so that you can insert back into the hole by cutting 1/2 inch of the plastic to slide in.


5. I use automotive Goop to glue the plastic piece to the cut aluminum and seal around the cut piece/plastic/surrounding. I then use silver touch up paint to blend in to the surrounding. Job finish. Total time 2 hours (excluding time to wait for the glue to dry).
The "Pro" of using this method is it will provide an access point to replace fuel tank vent valve in the future should it go bad without requiring to drop the tank (a lot of labor).
The "Con" cutting the hole of a Porsche 996TT (in my case all stock and in excellent condition).


I hope by documenting my journey of solving my fuel filling problem, it would give somebody in the future some ideas of the approach they may want to take to solve their problems.
Thank you 6speedonline's community of providing me with ideas and as a result, help me resolve my problem.
Best Regards
BV

 

Wow! Very good job and fix!!!! Happy for you, congratulations!!!!

 

Came out nice, great work!

 

Thank you jpflip and @JSBear for all your ideas and helps.
BV
​​​​​​​Best Regards

 

Was a pleasure to help you and learn at the same time ;-)