Fuel gauge needle bouncing
Thread Starter
Race Director
Joined: Aug 2000
Posts: 12,975
Likes: 22
Fuel gauge needle bouncing
It just started today. I filled up last night and noticed this morning that the needle is now bouncing back and forth. Anyone have a clue as to what may be causing this to happen?
Safety Car
Joined: Mar 2002
Posts: 3,729
Likes: 0
From: Vancouver, BC
Re: Fuel gauge needle bouncing (sd pacecar)
i have the same thing on my car. i was told that the sending unit floats in the tank and as the gas splashes back and forth, the needle bounces accordingly. when you come to a stop, the needle should stay put.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Fuel gauge needle bouncing (sd pacecar)
The mater is pretty well damped, so gauge variations due to driving is averaged out....the problem is the sending unit has some trash or rust in it....
needs taken apart and carefully cleaned, very carefully....wiper contact might be worn out also....it should read from nearly 0 to 90 ohms....as the float goes up and down....
GENE
needs taken apart and carefully cleaned, very carefully....wiper contact might be worn out also....it should read from nearly 0 to 90 ohms....as the float goes up and down....
GENE
Le Mans Master
Joined: Sep 2000
Posts: 9,078
Likes: 7
From: DFW TX
Cruise-In VII Veteran
St. Jude Donor '07
Re: Fuel gauge needle bouncing (mrvette)
There are a couple of companies on the web that you can mail you unit to and they will rebuild it. Doesn't cost to much either. I just live with mine. I tried to clean it and it didn't work. The wires that cause the resistance are very thin and if you break one it's rebuild time anyway.
Note, GM does not sell them anymore.
Note, GM does not sell them anymore.
Race Director
Joined: Sep 1999
Posts: 11,360
Likes: 382
From: Plano TX
Re: Fuel gauge needle bouncing (Budman78)
The gauge in my 71 didn't seem to have any dampening. Maybe something they added in later years? It would bounce all over on bumpy roads.
What I did on mine was I bought an autometer gauge for $29. I then disassembled it and transfered my old face plate and needle to the new gauge. It took some minor modification, but not that difficult. The mounting holes in the face plate had to be elongated and the needle hole enlarged a few thou.
I had to drill a new hole in the metal backing plate and elongate 2 of the other holes. It all installed well and looks factory. Even uses the factory connector, just had to swap 2 of the terminals.
The needle now goes to E with the engine off like modern cars. All the bouncing is gone. Rock solid needle.
What I did on mine was I bought an autometer gauge for $29. I then disassembled it and transfered my old face plate and needle to the new gauge. It took some minor modification, but not that difficult. The mounting holes in the face plate had to be elongated and the needle hole enlarged a few thou.
I had to drill a new hole in the metal backing plate and elongate 2 of the other holes. It all installed well and looks factory. Even uses the factory connector, just had to swap 2 of the terminals.
The needle now goes to E with the engine off like modern cars. All the bouncing is gone. Rock solid needle.
Thread Starter
Race Director
Joined: Aug 2000
Posts: 12,975
Likes: 22
Re: Fuel gauge needle bouncing (mrvette)
The mater is pretty well damped, so gauge variations due to driving is averaged out....the problem is the sending unit has some trash or rust in it....
needs taken apart and carefully cleaned, very carefully....wiper contact might be worn out also....it should read from nearly 0 to 90 ohms....as the float goes up and down....
GENE
needs taken apart and carefully cleaned, very carefully....wiper contact might be worn out also....it should read from nearly 0 to 90 ohms....as the float goes up and down....
GENE
