Jump to content

The RennTech.org community is Member supported!  Please consider an ANNUAL donation to help keep this site operating.
Click here to Donate

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recommended Posts

I’m having a weird ‘fuel thing’ with my 2001 Porsche 911… So, I’ve been thinking it gets terrible gas mileage, compared to my 986 Boxster. I expected slightly less, but, it seems pretty bad. Now, I can’t help but wonder if there’s actually something amiss about it.

 

When I fill the tank completely—and I mean ‘topping it off’ to get every last drop in, my fuel gauge usually looks like this (see the first picture, 01).

 

That picture was taken immediately after starting the car after filling up the tank (I was still at the pump). There have been occasions where the needle has gone all the way to just slightly past the 4/4 mark (just like the Boxster always does), but it usually lands below as seen in the photo.

 

However, today I was down to the warning light coming on telling me I’m low on gas. I stopped to fill it up and it only took about $30 worth. That’s odd, with gas prices here and filling up an almost empty tank, that should have been between $44 and $48 (that's what the Boxster runs). I tried to top it off but it wouldn’t take any more, as if the tank was full.

 

So, I got in the car and started it, and (just like before) this picture was taken immediately after starting the car after filling up the tank (I was still at the pump) - (see the second picture, 02).

 

Just barely over half a thank.

 

Any idea what could be going on with this?

01.jpg

02.jpg

Link to comment
Share on other sites

  • Admin

The fuel tanks and plumbing are very different between the C2 and C4 due to the front drive axle in the C4.

C4's historically have more fuel tank issues (mainly with calibration) because their are two sides to the fuel tank - a saddle bag layout.

 

If your tank is not filling all the way then I would suspect a crimped fuel fill hose or one of the other lines for vent return.

 

fuel tank 2WD.png

Link to comment
Share on other sites

does gas actually flow easily into your gas tank?

there is a known issue with the vent valve not opening and preventing tanks from easily filling.

If you are getting a good flow of gas from the pump, check your fuel sender, and then check the fuel gauge.

I think, I hope this is wrong, but I remember reading that if a gauge is faulty the entire instrument cluster needs to be replaced.  Loren?  RFP?

there are several articles on the filler valve issue, the search engine will be your friend.

good luck

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.