Author Topic: How would you cure  (Read 10991 times)

Offline Skunksmash

  • Senior Member
  • ****
  • Posts: 1398
How would you cure
« on: July 27, 2009, 02:22:43 am »
How can someone completely cure the wavy needle for the fuel gauge on these trucks? If there is one thing that I hate it's that wavy needle. Like I don't really need to know exactly how much fuel I have. And I have had 5 of these trucks in the past, all of various year models. They all had the same problem. The only thing I can think of would be to buy a brand new gas tank, and have a weld some baffles in there. I don't know any welder that will weld on a used tank lol. Any other ideas, or possible problems with my idea?

Offline Irish_Alley

  • Tim
  • Senior Member
  • ****
  • Posts: 13333
  • Family is not an important thing. It's everything.
Re: How would you cure
« Reply #1 on: July 27, 2009, 04:00:44 am »
some tanks have sponge like material in them i don't know where to get it tho ::)
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Captkaos

  • OWNER and Administrator
  • Administrator
  • Senior Member
  • *****
  • Posts: 18461
    • http://www.73-87chevytrucks.com
Re: How would you cure
« Reply #2 on: July 27, 2009, 05:53:45 pm »
You are relying on a float on a arm to give you a reading.  I waves because the arm in on a pivot and gas stays level.  On top of the fact that the tank is not a perfect square so when it gets low, all the fluid goes to one end or the other.  Newer vehicles have a vertical float so it is a little better but still it is going to fluctuate.

My 87 EFI has some baffles, but it still "moves".  A lot of work for something that isn't going to improve much.

Offline Skunksmash

  • Senior Member
  • ****
  • Posts: 1398
Re: How would you cure
« Reply #3 on: July 27, 2009, 07:40:11 pm »
Yeah I just want it to fluctuate more like a newer vehicle. Im fine with that. But mine waves all around and it looks so cheap and tacky. Maybe there is some way I could convert to a vertical float? Maybe I could get the whole apparatus from a newer truck and that might work? Anyone know if the newer truck's stuff will fit in our old tanks? I guess the best idea would be to get the whole tank assembly off a newer truck huh. Then hook everything up and have a nice non-wavy needle.
« Last Edit: July 27, 2009, 07:45:06 pm by Skunksmash »

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19181
Re: How would you cure
« Reply #4 on: July 27, 2009, 08:55:55 pm »
Don't use a baffled tank with an older sending unit. The gauge will not read correctly and you will run out of gas. You can use a non baffled tank with any years but unless you are using the efi sender don't use the baffled tank.

There's not much you can do with the stock set up to change the swinging gauge other than upgrade the gauge.
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Skunksmash

  • Senior Member
  • ****
  • Posts: 1398
Re: How would you cure
« Reply #5 on: July 27, 2009, 11:15:47 pm »
Don't use a baffled tank with an older sending unit. The gauge will not read correctly and you will run out of gas. You can use a non baffled tank with any years but unless you are using the efi sender don't use the baffled tank.

There's not much you can do with the stock set up to change the swinging gauge other than upgrade the gauge.

Sorry, guess i'm not real clear on what you are saying here. Probly cause i have not dealt with gas tanks much. Are you saying to get a new, yet unbaffled tank, and get the sending unit off a newer model? Or are you saying that there is absolutely no way around the problem except for upgrading the gauge? If so, can you tell me why the newer tank and unit out of a newer truck idea will not work? It seems to me like all you would need to do is maybe adapt some of the cabling (or wires or whatever) and the newer better setup should work just fine to get rid of the problem. Please fill me in on why this won't work.

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19181
Re: How would you cure
« Reply #6 on: July 28, 2009, 06:34:12 am »
I'm saying there are issues using the baffled tank with your sending unit. Some people think that running a baffled tank will cure the problem which it won't. The 1987 fuel tank contains a fuel baffle which can cause interference with the fuel sender float arm and not allow the fuel gage to read below 1/4 tank of fuel. If the truck is equipped with dual fuel tanks, this condition can occur in either tank. The 1987 fuel tanks can be identified by removing the fuel tank and fuel tank sender and checking for the reservoir (plastic) which is attached to the bottom of the tank by two studs which are approximately 4" from the center of the fuel sender unit. The gauge is over sensitive and replacing the gauge is the only real cure I've seen.
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Skunksmash

  • Senior Member
  • ****
  • Posts: 1398
Re: How would you cure
« Reply #7 on: July 28, 2009, 07:21:16 am »
So in other words, using a tank/unit out of a newer truck that doesn't have the problem... won't fix the problem. It's actually the fault of the gauge itself, and not the tank/unit. Do i got this right?

The only problem I got with the whole getting a different gauge thing is this: I want to keep the original recessed gauge look. I have no love for that flat faced look that a lot of people do. I like to keep things as stock looking as I can, I think GM was spot on with their design ques and I like the way they already look. Is there a better gauge that is not so sensitive, that I could keep in the recessed little hole and have it all still look factory? I have never seen any, but you guys have probly run across something I havn't.

Offline zieg85

  • Global Moderator
  • Senior Member
  • ****
  • Posts: 7595
    • 73-87 GM squarebody extended cab and conversions up to 91 R/V series
Re: How would you cure
« Reply #8 on: July 28, 2009, 09:32:29 am »
Just a thought... Consider a tach cluster... The gauge is moved down where the empty/clock location.  Those, being smaller may not bother you as much with the movement.  My $.02
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
https://www.facebook.com/groups/248658382003506/

Offline Captkaos

  • OWNER and Administrator
  • Administrator
  • Senior Member
  • *****
  • Posts: 18461
    • http://www.73-87chevytrucks.com
Re: How would you cure
« Reply #9 on: July 28, 2009, 12:14:36 pm »
If you want to get rid of it, buy a new tank designed to fit your truck and mount an aftermarket verical slide in it.  The new model sending/pump units are HUGE and you would be hard pressed putting one in a 73-87 tank.

Of all things on the truck to worry about this would be at the very bottom of the list.

Offline Skunksmash

  • Senior Member
  • ****
  • Posts: 1398
Re: How would you cure
« Reply #10 on: July 28, 2009, 12:48:05 pm »
Not for me. For me it's at the top of the list, everyone's priorities for their project are different. My truck is mechanically sound (knock on wood and all) and doesn't need anything other than what little I can come up with to do to it. Not to mention it's not really like an obscure body scratch or something. It's staring me right in the face every time I drive. I just can't deal with it.  ;)
« Last Edit: July 28, 2009, 12:51:47 pm by Skunksmash »

Offline ron350

  • Newbie
  • Posts: 43
Re: How would you cure
« Reply #11 on: July 28, 2009, 01:46:58 pm »
   Skunkmash

I have the same problem you have and my gas gauge and it only started waving around a few years ago. The needle will swing about ¼ of a tank and back when I am driving.

Some of the problem is in the sensitive gauge and some of the problem is in how poorly the sending unit was designed.
Part of the sending unit problem is that the two most important contacts are riveted and not soldered.

The other problem is that the float arm catches ground by touching the housing the rod mounted through. The float arm should have a solid ground attached between the housing and the float arm to eliminate the problem.

It would be nice if we could come up with a voltage smoothing circuit to cure the problem without pulling the tank.


« Last Edit: July 28, 2009, 01:53:01 pm by ron350 »
1975 C10 step side stock with 350 two bbl. & 350 trans.

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19181
Re: How would you cure
« Reply #12 on: July 28, 2009, 04:32:46 pm »
Build a wheatstone bridge
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline ron350

  • Newbie
  • Posts: 43
Re: How would you cure
« Reply #13 on: July 28, 2009, 05:31:54 pm »
VileZamboni
 If you would sketch a diagram I will solder it up and give it a try.

 
1975 C10 step side stock with 350 two bbl. & 350 trans.

Offline Lt.Del

  • Andy aka:SgtDel
  • Senior Member
  • ****
  • Posts: 3864
  • DelbridgePhotography.com
    • www.delbridge.net
Re: How would you cure
« Reply #14 on: July 28, 2009, 07:53:27 pm »
Skunk, let me guess.  Each time you are driving and the needle goes crazy, you look like the picture on your personalized picture, right?