Author Topic: Bouncing Fuel Gauge  (Read 5732 times)

Offline DirtyLittleSecret

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Bouncing Fuel Gauge
« on: July 31, 2007, 02:53:50 PM »
Okay, so I've got dual tanks on this tank, and the gauges like to "flutter" a good 1/4 of a tank.  Does'nt matter if I have it on the R or L tank, and it stops only when the tanks are FULL.  Are these tanks baffled to keep this from happening or it this a normal issue?  Not really a problem, but annoying nonetheless!
78 K20: fresh 350, SM465, NP205, 4" Pro Comp, & working hard!
65 Jeep J300: 13.5:1 383, TH400, NP205, mostly NOS. 
88 Toylet LandCruiser FJ62: LT1, 4L60e, 3" OME, Aussies.
06 VW TDi: DD@72mpg.

Offline ccz145a

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Re: Bouncing Fuel Gauge
« Reply #1 on: July 31, 2007, 03:52:21 PM »
Do you mean bouncing, as in bouncing like a speedometer bounces when there is a kink in the cable, or bouncing as in real slow like as you describe how fluid in a tank would slosh around?

I guess what I am trying to say is: fast or slow.

Fast would most likely be a poor ground up near your gauge in the dash. I have no idea what it would be if slow... The sender is in the middle side to side and fuel sloshing around does not cause this behavior in my experience.
1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
11MPG Downhill w/tailwind (but there ain't no hills here)

Offline Captkaos

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Re: Bouncing Fuel Gauge
« Reply #2 on: July 31, 2007, 04:31:21 PM »
Non-EFI tanks do not have baffles in them and the GM gauges are not know for being completely accurate.  Is it moving when the truck is sitting still, or moving when you are hitting bumps/dips etc.  Once the fuel gets low, the gauge will fluctuate some on different inclinations.

Offline DirtyLittleSecret

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Re: Bouncing Fuel Gauge
« Reply #3 on: July 31, 2007, 10:46:20 PM »
Its definitely a fuel "slosh" feel to it.  It fluctuates slow n' steady.  It will sit still if parked and not breathing.  Ruled out the bad ground today (new), but didnt know if there were baffles.  Darn.
Thanks!
78 K20: fresh 350, SM465, NP205, 4" Pro Comp, & working hard!
65 Jeep J300: 13.5:1 383, TH400, NP205, mostly NOS. 
88 Toylet LandCruiser FJ62: LT1, 4L60e, 3" OME, Aussies.
06 VW TDi: DD@72mpg.

Offline Lt.Del

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Re: Bouncing Fuel Gauge
« Reply #4 on: August 01, 2007, 03:20:39 PM »
My ole 79 pickup does that, and it is just a single tank.   Starting from a stoplight or heaving breaking will cause the needle to go up and down quite a bit.  It doesn't bother me, i just read it when i am at a steady speed or completly stopped. 

Offline Captkaos

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Re: Bouncing Fuel Gauge
« Reply #5 on: August 01, 2007, 03:37:19 PM »
Its definitely a fuel "slosh" feel to it.  It fluctuates slow n' steady. 

There isn't a "fix" to it because the float is on an radial arm not in a channel so as fuel sloshes, the gauge will move.  A baffled tank won't make a difference either as the sending unit is the same configuration, my 87 does it.

Offline stevens

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Re: Bouncing Fuel Gauge
« Reply #6 on: August 20, 2007, 09:22:32 AM »
My 78 does that! people just laugh at it but does not really bother me  :P