My fuel gauge drops down really fast then flies way back up again - it swears it is empty one minute and then all of a sudden it tells me that, yes, it actually has a half tank of gas - it literally is all over the place - the thing is whacked out.

Its not a big deal - but is there anyway I can fix this myself? is it tough? does anyone have a writeup?

 

Isn't there a float in the gas tank that determines the current sent to the gauge? Maybe its getting stuck in the tank?

 

yeah geez I dont know - that might be it - it seems to happen mostly at half tank and below where the gauge will visibly drop and then bounce back up again - and do that all over again...
if it is the float in the tank what are the causes of it getting stuck? how can it become unstuck?

also if it is the float - and it was getting stuck - how would the gauge (and hence the float) go back up after going down?

 

You could test the sender resistance:
http://www.4crawler.com/4x4/4R_TechI...tml#Electrical

If it is stable then the culprit is likely the gauge or the voltage stabilizer that operates it in the instrument cluster.

 

This happened to me a while ago... it came from a low-voltage state in/across the truck. Replacing my alternator fixed it.

 

I would say check the ground.

 

Check and see if someone put a "John Kerry" sticker on it. That would be enough to cause that...

(Sorry, I couldn't help myself. It's a joke and not meant to inflame those who get inflamed by these things, provoke those who get provoked by them or incite those who get incited. It was not meant as a political commentary or to promote additional discussion on the topic. It was merely a satirical comment, designed to create a light-hearted atmosphere. If you took it seriously, you should seriously consider checking eBay to see if they have a life you might be able to get.)

 

i am inflamed, provoked AND INCITED!

 

You could always just "bump" the thread, but no, you have to incite inflamation.

 

Incite inflamation? 5-star Thai food does that to me...

 

sounds to me like a bad resister in the tank.

 

My 87 had the same issue. I replaced the sending unit in the tank to correct. If the newer models are the same you will have to drop the tank. A bit of a pain but not high tech.