Ran out of gas last week - Page 2

mpanten · #21 (**permalink**) 08-11-2009, 09:55 AM

I have spent several hundred dollars trying to get mine calibrated. Bought a new sending unit and gauge. paid two people to work on it. still reads full all the time. It's annoying.

madmaxx · #22 (**permalink**) 08-11-2009, 01:21 PM

The reason the gauge drops so fast after half tank is due to the geometry of the tank, you will note how it slopes up towards the rear. It is very simple to adjust the sending unit. open your trunk, remove carpet, remove access plate and you will see the screws to the sending unit. Remove and bend rod to get the reading you want. Note this would not be a good time to start smoking. Also be carefull what you tighten on the sending unit the float and associated arm must move freely so it will move when the level in the tank drops. I have to admit my gauge works like a champ and is calibrated well. I learned how to calibrate one on my previous BDR.

RedBarchetta · #23 (**permalink**) 08-11-2009, 01:28 PM

There is a procedure to bench-calibrate these things. Involves pulling out the sending unit/float, checking the ohms at the top and bottom of the swing, measuring the tank dimensions, and then carefully bending the float rod so that the final "stroke" is optimized. It sounded too involved for my tastes (I have other things that I'd rather take apart and tinker with), so I've just become accustomed to making a hard charge for a gas station when I'm at 1/2 full.

-Dean #747

Silverback51 · #24 (**permalink**) 08-11-2009, 02:42 PM

Quote:

Originally Posted by RedBarchetta

There is a procedure to bench-calibrate these things. Involves pulling out the sending unit/float, checking the ohms at the top and bottom of the swing, measuring the tank dimensions, and then carefully bending the float rod so that the final "stroke" is optimized. It sounded too involved for my tastes (I have other things that I'd rather take apart and tinker with), so I've just become accustomed to making a hard charge for a gas station when I'm at 1/2 full.

-Dean #747

I'm with you Dean. It's not worth the effort.

After all, it does not add any HP.

madmaxx · #25 (**permalink**) 08-11-2009, 05:32 PM

It not really not that hard and kinda fun, run your tank a low and pull the sending unit. No need to measure ohms. Pull the unit, measure the depth of your tank and adjust your float arm. Detailed instructions on any of the sending unit websights. Check out VDO or ask nissonger for a copy.

scootter · #26 (**permalink**) 08-11-2009, 09:07 PM

I pulled the sending unit and filled the tank half way with gas then bent the float till I got the half tank reading. When mine reads full, it's full. When it reads empty, it's empty. It took a couple of minutes to do. Like was said earlier, due to the shape of the tank, the top half of the tank holds more then the bottom half.
I never let mine get much below half. With the shape of the tank and the fuel pickup, the gas sloshes to the back of the tank under hard acceleration and the fuel pump will suck air. Not a cool sight to have your car die after blowing by someone!!

Scott

Got the Bug · #27 (**permalink**) 08-11-2009, 09:25 PM

Quote:

Originally Posted by scootter

I never let mine get much below half. With the shape of the tank and the fuel pickup, the gas sloshes to the back of the tank under hard acceleration and the fuel pump will suck air. Not a cool sight to have your car die after blowing by someone!!

Scott

I never let mine go below 1/8 of tank.

Seriously, I'm not too concerned about calibrating the gauge on my car now that I know where empty is.

cdog · #28 (**permalink**) 08-12-2009, 08:00 PM

I can run mine all the way to 'E', whereupon it will take about 16.5-16.7 gallons. It plummets from 1/4 tank to E in like 20 miles...

For the record, I have a 520 Ford and can get 15+ mpg on the highway in 5th at 75 mph.

powerslide · #29 (**permalink**) 08-13-2009, 06:16 AM

I dunno...for what we all paid for these cars, we should have fuel gauges that are accurate, and perform as intended. My SPF has a Fuel Safe fuel cell and am currently trying to resolve the inaccuracy issue. It appears there is an ohm incompatability between the ohm rating of the Smiths gauge and the Centroid sending unit located in the fuel cell. The folks at Centroid are extremely helpful and will walk you through the steps that you need to take to resolve the issue. They now have a programmable sending unit that will make readings on your Smiths gauge accurate down to 1/8 ths of a tank.
Its obvious from our thread that fuel gauge inacccuracy with SPF's is significant; and we shouldn't have to accept this problem as being "OK" or having to resort to "guessing" tank fuel level. This goes beyond the "tinker factor" as it affects the reliability of the vehicle (being stranded is not part of the joy of ownership that SPF folks expect), maybe SPF needs to issue a TSB dealing with the problem?

PANAVIA · #30 (**permalink**) 08-14-2009, 01:17 AM

How about a 2 gallon reserve tank on top of the first one in the trunk on the back wall. --

Ken Oikawa · #31 (**permalink**) 08-14-2009, 07:31 AM

Quote:

Originally Posted by PANAVIA

How about a 2 gallon reserve tank on top of the first one in the trunk on the back wall. --

In the trunk, I have a 5 gal reserve fuel cell connected to the main tank.
It's connected using -10 hose and a manual shut-off valve; open the valve and main tank will be fed by gravity. You lose some trunk space, but better than being stranded.

Cheers...