Fuel tank sender

[rjc157]

I know this thread has been beaten to death but I bought a new fuel tank sender hoping that it will eliminate the jumping up and down of the needle while driving but no luck I do get a steady reading at rest I added an additional ground from the sender to the car is there a fix or just not look at the gauge while driving very frustrating

 

[GregW]

A couple old threads that may help.
https://www.britishcarforum.com/bcf/showthread.php?79355-How-to-smooth-out-a-jumping-fuel-gauge
https://www.britishcarforum.com/bcf/showthread.php?71721-fuel-sending-unit-float-position

 

[RAC68]

Hi Ralph,

Other then installing a ground between the sender base and float arm with a piece of flexible woven solder removal strip. I believe there is a electrical component that someone added to the gauge to calm down needle movement. In effect, it cuts down the signals sent from the sender to slow down reading changes. I will provide it once I find it or maybe other can post it.

Good luck
Ray (64BJ8P1)

 

[rjc157]

Ray are you having the same issue

 

[Keoke]

More upscale British cars of the period utilize a small "voltage stabilizer" to smooth the sender voltage swings fed to the fuel gauge. All Jag/Daimler Saloons as others use them. They were produced by Lucas to match each gauge.
I never tried to use one in the Healey.

 

[RAC68]

Ralph,

I added the ground wire to the arm and keep the tank relatively full. I do get gauge fluctuation but it is not causing any difficulty. I was thinking of applying some stabilization to the feed as Keoke or other have suggested but just haven't gotten to it.

One last point, the correct mounting of the sending unit is with the float toward the front of the car. This orientation seems to produce less gauge movement then if the float is directed toward the rear.

Ray (64BJ8P1)

 

[Keoke]

I was thinking of applying some stabilization to the feed.

Well Ray:
You might try using a half or full wave diode rectifier.
Where perhaps the only real critical requirement for the diodes would be that they have the smallest forward voltage drop you can find.

OH!! as you say"Good Luck":highly_amused:

 

[steveg]

I found this inexpensive Porsche gauge stabilizer helps smooth out the swings:
https://www.pbase.com/stevegerow/image/101096144

 

[RAC68]

Hi Steve,

Can you provide details on the Porsche gauge stabilizer?

Thanks,
Ray(64BJ8P1)

 

[steveg]

Hi Steve,

Can you provide details on the Porsche gauge stabilizer?

Thanks,
Ray(64BJ8P1)

Better idea - Moss makes a solid-state voltage stabilizer used in newer Brit cars. See:

I will order one of these and report back on how it works.

 

[John Turney]

The Moss voltage stabilizers are for the gauges that use bimetallic strips. I don't know about later Healeys, but my '57 uses a moving-coil meter. These are the ones that act rapidly to changing inputs, whereas the bimetallic strip meters act slowly.

 

[RAC68]

Thanks Steve,

Ray (64BJ8P1)

 

[Bob_Spidell]

Been a while since I messed with one, but I don't believe the fuel part of the safety gauge in our Healeys is the bimetallic strip type; I think it's closer to a moving coil type (my gauge doesn't 'drift up off the lowest reading' when I turn the ignition on; it shoots up). Before you order, check out https://www.mossmotors.com/graphics/products/PDF/131-555.pdf

 

[steveg]

The Moss voltage stabilizers are for the gauges that use bimetallic strips. I don't know about later Healeys, but my '57 uses a moving-coil meter. These are the ones that act rapidly to changing inputs, whereas the bimetallic strip meters act slowly.

There are some online articles about building your own. Lucas used to use a bimetallic strip stabilizer but I don't think the gauges themselves had the bimetallic strip. The stabilizer puts out 10V so it may be the case that our gauges read low (but steady!) because they're expecting the 12V from the battery.

My current Porsche stabilizer seems to make the gauge run low, in that when clear full, the gauge reads around 3/4 tank.

Since the device is cheap, think I'll order one and see if it works better than the Porsche item.