excessive pressure in the gas tank? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

mountainman · 08-07-2013, 06:52 AM

Headed over to a friends house to try to figure out why he can"t get gas to go into his 04 Boxster S. He is almost empty and tried to gas up at 2 locations that he regularly uses, but it kicks it back out as if there were a lot of pressure in the tank keeping it from going in. Anyone had this problem or have a clue as to what to check out.

thom4782 · 08-07-2013, 07:04 AM

Porsche issued a technical bulletin in this issue. Apparently, there are a couple of hoses in the fuel tank that get in the way and restrict the fuel flap from opening completely. The fix is to use zip ties to move the hoses out of the way. IIRC the procedure involves removing the fuel sending unit.

mountainman · 08-07-2013, 07:47 AM

Quote:

Originally Posted by thom4782

Porsche issued a technical bulletin in this issue. Apparently, there are a couple of hoses in the fuel tank that get in the way and restrict the fuel flap from opening completely. The fix is to use zip ties to move the hoses out of the way. IIRC the procedure involves removing the fuel sending unit.

Thanks Thom, Going to meet him later today at the gas station and see if I can get more insight into how it is acting. He is a great guy and good neighbor, but is a retired pediatrician and it seems that babies and Porsches are not enough alike to help him figure out some of these problems so I help out when I can.
Any idea how I could access the tech bulletin for more info?

thom4782 · 08-07-2013, 08:27 AM

The TSB title is Fuel Tank Hose Modification. If you're a Contributing Member in the Renntech forum, you can download it from the DIY section. Not sure if I can download the and share because of copyright limitations.

PS: Picture of hoses zip tied in place

Laredo · 08-07-2013, 08:32 AM

Sometimes is the venting valve of the gas tank, depending on the year check the fusible in my case 2002 is E6.

mountainman · 08-07-2013, 08:56 AM

Quote:

Originally Posted by Laredo

Sometimes is the venting valve of the gas tank, depending on the year check the fusible in my case 2002 is E6.

Thanks I'll check that.

BYprodriver · 08-07-2013, 10:01 AM

Turning the hose nozzle 180degrees upside down usually helps

mountainman · 08-07-2013, 10:50 AM

Quote:

Originally Posted by BYprodriver

Turning the hose nozzle 180degrees upside down usually helps

Tried that and by going very slowly was able to get in about half a tank. Also checked the E6 fuse ( on the 04 diagram I could not find any listing for a fuse dealing with the fuel tank vent. Looks like it may be time to go into the tank. I am not sure if friendship extends that far.

mountainman · 08-07-2013, 10:53 AM

Quote:

Originally Posted by thom4782

The TSB title is Fuel Tank Hose Modification. If you're a Contributing Member in the Renntech forum, you can download it from the DIY section. Not sure if I can download the and share because of copyright limitations.

PS: Picture of hoses zip tied in place

Thanks Thom, I will have to join renntech and check it out. Who knows, mine may do it someday. Still not clear on what is actually happening to cause the problem, but maybe the TSB will explain in detail how it is malfuncting. Thanks again

Laredo · 08-07-2013, 11:46 AM

Quote:

Originally Posted by mountainman

Tried that and by going very slowly was able to get in about half a tank. Also checked the E6 fuse ( on the 04 diagram I could not find any listing for a fuse dealing with the fuel tank vent. Looks like it may be time to go into the tank. I am not sure if friendship extends that far.

The technical name is onboard refueling vapor recovery (ORVR) valve. On all 2000 and newer Porsche cars. An electronic onboard refueling vapor recovery (ORVR) system including an electrically operated ORVR valve that selectively opens and closes a fuel vapor path between the fuel tank and a collection canister.

mountainman · 08-07-2013, 12:00 PM

Quote:

Originally Posted by Laredo

The technical name is onboard refueling vapor recovery (ORVR) valve. On all 2000 and newer Porsche cars. An electronic onboard refueling vapor recovery (ORVR) system including an electrically operated ORVR valve that selectively opens and closes a fuel vapor path between the fuel tank and a collection canister.

Thanks, OR/VR is one of the things listed in E6 on the fuse diagram which calls for a 7.5 amp fuse. It actually had a 5 amp fuse in it that was not blown and I replaced it with the correct 7.5 and it made no difference. It could be the valve itself. I'll do some more research. Every small piece of info helps to understand what is happening.