Fuel Gauge is off ....

[George Zeck]

Hi All -

One last items I am working on. My fuel gauge is (reasonably) accurate for the first half of the tank.

Once I get near the 50% mark - it fluctuates wildly F to E (& much more than normal 'slosh').

I have replaced the gauge (ebay) a number of years ago and have dealt with this for awhile now (I always had more pressing repairs). I believe it worked 'properly' at one time and would not rule out the possibility I zapped it when I wasn't paying attention to a battery hook up and switch "+" & "-" (Oooops).

The gauge is Smith "BF2300/02" Supposedly from a Spridget, forget what year. (Also, out of the car). 2 connectors on the back side.

The sending unit is probably 8ish years old. (& still on the car).

I remember reading prior posts that the two units (gauge & sending unit) could be on different resistance / signals. Being the gauge does work (the needle moves) - would the first guestimate repair be to swap out the sending unit?

Could anyone suggest a course of action to start on? Would the probable culprit be the sending unit or not?

Thanks-

George

 

[smaceng]

George,
Using Moss Europe parts list, I was able to track down your gauge, BF2300/02, it was used from Oct 64 to Nov 67 in the MGB. That gauge used a voltage stabilizer. The Midget did not start using a stabilizer until the 1275 in Oct of 1966. My guess is that you have a mix match of parts, which has caused the gauge to work incorrectly.
Scott in CA

 

[Sarastro]

The symptoms you describe are typical of a bad sending unit. A mismatched sending unit and gauge wouldn't cause the indicated level to drop suddenly at some point as the fuel level in the tank drops. Neither would a zapped gauge, and the gauges are pretty hard to zap, in any case.

 

[reddsprite]

I have a similar issue with fuel guage/tank-As guauge level approaches 1/2 tank car has all the symtoms of being out of gas....not! First I thought it was unions of rubber fuel line and the steel hard line allowing air in the line, and now I am going to replace the sending unit-fortunately this hasnt happened far away from home-this is frustrating stuff!

 

[RickB]

In my MK2 Sprite when I connect the wires to the gas gauge it just pegs all the way to the right. So I've left it unplugged. :frown:

 

[nomad]

Rick, I think that means you have a dead short in the wire to the tank. Opposite would be a bad connection would read empty. Least as memory serves. If I'm wrong I'm sure someone will correct me. The sending unit is just a contact moving over a series of winding's that give a varying resistance. When the guage drops I believe it is because the float lever arm contact lost its contact with the windings. Again memory.

Kurt.

 

[RickB]

Kurt, that makes sense although I seem to remember shortly after buying this car that I ran a wire from the gauge to the sender and had the same result.
Since I am no longer sure I will do that again some time.

 

[Morris]

Odometer = fuel gauge.

Problem solved! :wink:

 

[RickB]

Odometer = fuel gauge.

Problem solved! :wink:

Also non working.
:frown:

 

[nomad]

Rick you also could have the guage hooked up backwards, I believe.

Kurt.

 

[JPSmit]

Rick you also could have the guage hooked up backwards, I believe.

Kurt.

Ooo a gas gauge/tank that goes from empty to full as you drive - you mean if we just reverse the wires? Why didn't "they" tell us that? It's a conspiracy man.

 

[markberry]

Hi George,
This is a good link to help with fuel gauge problems
https://mgaguru.com/mgtech/electric/fg_01.htm
Hope it helps
mark

 

[George Zeck]

Thanks Mark.

Going to get new / matching sending unit since my gauge looks great and match it up with corresponding sending unit.

I've been using the "odometer method" for a while; About to make a very long trip and would prefer to have a working gauge.

Tx-

George

 

[bug_sixty]

I was under the impression that if you coverted a BE to neg. ground the fuel gauge read backwards

 

[Bayless]

Fuel gauge does not care about the polarity.