What circuit or component keeps the fuel gauge from wobbling around as the gasoline moves in the tank ?
I need to fix this as it is most annoying... while driving the gauge does not stay steady as in all other vehicles I have had.. I assume there is some thing like a capacitor or electrical dampening circuit that smooths out the signal from the tank float.

Any leads would be appreciated

1995 LS 327K

 

It is mounted to the pump in the tank. It may have broke loose. If your gonna pull the pump the fix it you may as well replace the pump. Use a delphi or acdelco pump. The other cheap ones last about a year.

 

I agree. Mine used to bounce around and then it wouldn't read above a half a tank. Installed a new pump which included the level sensor and it's been working great. Watched a Youtube video first which made it "fairly" easy.

 

Thanks for the tips however the tank, fuel pump and sending unit are all new. The gauge bounced around with the original sender unit also. the sender unit can not be the problem. Think about this logically... The gas is sloshing around in the tank ..therefore the sender float is constantly moving also... therefore the resistance of the circuit is always changing.... the gauge (absent any controls) would move around also.

There must be some circuit or device the smooths out and averages the constantly changing signal to provide a steady gauge reading over the short term.

Anyone know how this works ? Thanks

 

Did you search the site for fuel gauge problems? There are several threads dealing with this. It could be the gauge itself, or possibly a buffer module.

 

Yes I did a search prior to posting. The predominant answer is to replace the pump/sending unit. there are references to a module (pump relay most likely?) but no specifics regarding my 1995 model. Notably missing is an explanation of how the fuel gauge system really works aside from the sender being a variable resistor which is obvious..

I would be most interested in in the gauge controls and buffer module you refer to.

 

 

Hi - Thanks for the lead.

Unfortunately that may not be relevant to my vehicle. The post refers to a 1997 Jimmy.... I have a 1995 Blazer engine code W... More specifically it is one of the 'oddball' versions that has an OBD1 compliance sticker under the hood but has an OBD2 connector under the dash. It puts out Pxxxx format codes.

In reading the Chiltons Manual I have, it's described as having a VCM-A engine controller. (deduced because of the Pxxxx style codes) The related schematic diagrams do not show a "Buffer Module". The fuel sender is shown directly feeding the gauge. Any other ideas ? Anyone have the same model Blazer ?

 

I still think its on the pump that is the problem. You can buy bad units

 

I assume you mean the sender unit..... The gauge moved around with the original one. I installed a new one.. the gauge still moves around. I tested the original one .. its fine...There must be something that smooths out the float movements to display on the gauge. When not moving the gauge it steady ... move a bit and the gauge swings back and forth following the rocking fuel level...

With all the experience here someone must know what the answer is.