GMC Repair: fuel gage needle, gmc savana, gm vehicles

Question
I'v got a 1998 GMC Savana 3500 series van, The problem is the fuel gage needle is vibrating constantly and is only acurate when tank is full, otherwise the needle jumps all over the scale once i drive appox 30 mile after a complet fill up

Answer
This has been a problem with GM vehicles for the last 50 yaers. I own several GM vehicles and they all do the same thing.

It CAN be fixed but is very very difficult to diagnose.

There are only 4 possibilities:

1. Faulty fuel meter in the fuel tank.
2. Faulty fuel indicator on the dash.
3. faulty wiring from # 1 to # 2.
4. The BAFFLE in the fuel tank has come loose. It is simply
  a 12" square plastic pan that is attached to the fuel
  tank of which your fuel meter and fuel pump set inside
  of. This BAFFLE has a tendency to come loose and thus
  your problem. Soultion is to replace the fuel tank and
  the fuel meter as the fuel meter always gets damaged
  when the BAFFLE comes loose.


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