| Author |
Message |
Max Welton
Samba Member
Joined: May 19, 2003
Posts: 11028
Location: Black Forest, CO
|
|
| Back to top |
|
 |
Ossipon
Samba Member
Joined: May 12, 2021
Posts: 609
Location: KS
|
 Posted: Sat Jun 21, 2025 6:12 am Post subject: Re: Fuel Gauge Accuracy |
 |
|
You did not. The tank (unless you dented it severely) is 10.6 Gal. I had that same problem with a SuperBeetle I had. I literally had to remove the nozzle, wait a second and then start again. I never had that problem with trunk filled gas tanks. If I did not pull the nozzle, it would continue to act like it was full, even when I knew it wasn't.
_________________
Ossipon
--Two truths in life: Volkswagens Rust and everything will die at some point --
VWs in my life:
Air
Type 1 - 59, 62, 63, 71 Super 68 KGhia/ Type 2 - 59 Single Cab / Type 3 - 64 Notch
Water
GTI 83, Jetta 81, 85, 87, 91 TDI, 98 TDI, 09 / New Beetle 99 / SportWagen 05, 13 / Tiguan 18 / T3 92 /Taos 24... And don't about me and my experiences with my Dasher and Quantum |
|
| Back to top |
|
|
Max Welton
Samba Member
Joined: May 19, 2003
Posts: 11028
Location: Black Forest, CO
|
|
| Back to top |
|
|
Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 23358
Location: Kimball, Mi
|
| Posted: Sat Jun 21, 2025 12:58 pm Post subject: Re: Fuel Gauge Accuracy |
|
|
| Max Welton wrote: |
Yeah, that's why I generally average several tanks to calculate mpg. Across the four fill-ups I have so far I have 29.12 mpg.
Max |
Sounds like you've got your MS dialed in pretty good. Especially for your altitude (I know you're changing altitudes when you go almost anywhere). You mentioned it several times when dialing your Squareback.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
|
|
| Back to top |
|
|
Max Welton
Samba Member
Joined: May 19, 2003
Posts: 11028
Location: Black Forest, CO
|
| Posted: Sat Jun 21, 2025 7:30 pm Post subject: Re: Fuel Gauge Accuracy |
|
|
| Bobnotch wrote: |
| Sounds like you've got your MS dialed in pretty good. Especially for your altitude (I know you're changing altitudes when you go almost anywhere). You mentioned it several times when dialing your Squareback. |
Thanks. I have the 2nd barometer option (basically a second map sensor open to the atmosphere) so it can correct for changes in ambient barometric pressure (weather and/or altitude). Also, I'm running it closed-loop which makes experimenting a lot safer.
Max
_________________
1967 Type-3 Fastback
Under the Knife https://shoptalkforums.com/viewtopic.php?f=24&t=151582
Home Stretch https://www.thesamba.com/vw/forum/viewtopic.php?t=767836 |
|
| Back to top |
|
|
Max Welton
Samba Member
Joined: May 19, 2003
Posts: 11028
Location: Black Forest, CO
|
| Posted: Sat Jun 21, 2025 7:47 pm Post subject: Re: Fuel Gauge Accuracy |
|
|
| Ossipon wrote: |
| You did not. The tank (unless you dented it severely) is 10.6 Gal. I had that same problem with a SuperBeetle I had. I literally had to remove the nozzle, wait a second and then start again. I never had that problem with trunk filled gas tanks. If I did not pull the nozzle, it would continue to act like it was full, even when I knew it wasn't. |
I will have to start doing that.
Max
_________________
1967 Type-3 Fastback
Under the Knife https://shoptalkforums.com/viewtopic.php?f=24&t=151582
Home Stretch https://www.thesamba.com/vw/forum/viewtopic.php?t=767836 |
|
| Back to top |
|
|
sctbrd
Samba Member
Joined: May 06, 2013
Posts: 281
Location: Moravia, Czech Republic
|
| Posted: Wed Jul 09, 2025 10:05 am Post subject: Re: Fuel Gauge Accuracy |
|
|
I drained my t34's tank dry to check it for debris and blow out the tunnel tube.
New sender unit from ISP West.
When refilling, I check the ohms vs gauge reading for every 5 liters added (standard gas can here in CZ).
Results:
Dry- halfway on the teardrop shape to the left of R, 85 ohms
5L- Just below the R level mark (reserve, should be 5L), 80 ohms
7.5L- Top of the R level mark, 71.5 ohms
13 L- at 1/4 level mark, 54 ohms
20L- at the "1" in 1/2, 40 ohms
30 L- just below 3/4 mark (or just below "1" in 1/1), 30 ohms
40 L- slowly crept up to the FULL mark, right on the nose, 10.5 ohms.
So, after making sure my gauges were grounded well, and adding a ground wire to the tank sender, Im happy with it.
I made sure to wait a while for the sender to fill, especially at the top end, since the holes fill up slower, and I imagine the angle of the tank had something to do with it.
(yes Im a data nerd when it comes to electrics  )
Maybe this will help someone. Ive seen a post about the ISP sender not giving a decent reading, but Im happy with mine.
|
|
| Back to top |
|
|
Ceckert64
Samba Member
Joined: September 16, 2015
Posts: 2109
Location: Huntington, WV for now
|
|
| Back to top |
|
|
Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 23358
Location: Kimball, Mi
|
| Posted: Thu Jul 10, 2025 10:09 am Post subject: Re: Fuel Gauge Accuracy |
|
|
| Ceckert64 wrote: |
| I had a new sender (may have been ISP) and found the float started absorbing fuel and was sinking/ not fully floating, it’s 2 pages back on my thread but here’s what it looked like. The OG vw one is fully floating. It may be worth checking |
I haven't run into a new one doing that, but I have had a sticking float before. You'd be surprised what you run into over the years of working on cars. I've had a float stick toward the bottom of the tube, and only barely allowed a gallon into the tank. That's when I started keeping track of my mileage as a back up to the gauge.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
|
|
| Back to top |
|
|
|
