gas guage not working all the time

I have a 89 b2200 5 speed and my fuel gauge only works when I get up to 55 MPH and keep it there for 4-5 miles and it will continue to work until I slow down then it drops below empty. I have unplugged the sending unit and cleaned the connectors but its still the same. If anyone has any advice on this I would greatly appreciate it.

When you took apart the sending unit did you bend the tab back into contact with the fins of the sending unit? Mine has been reading wrong for months... Recently pulled mine apart and bent the tab back and been working since

I didn't really see anything out of place but I have to put a carrier bearing in this weekend so I'll take a closer look while I'm under there. You are talking about on the plug outside of the tank correct. Thanks for the info

No I'm talking about the actual fuel level sender... What the float hinges off of... You have to open the little box and bend the tab to come into constant contact with the fins of the sending unit... As the flat moves up or down the tab slides on the fins... Resistance is measured by this unit to sure you your gas level in the in dash gauge

I've cleaned my own fuel sending unit, similar to what you describe. But I can't figure why the poster thinks this is related to speed of the truck. If it's a fuel sender issue, the factor should be the level of fuel or going around a turn, something that makes the float move to a position where there is no contact. There should be a smooth change in ohms as the float moves (by hand outside the tank or by gasoline inside the tank) through its range.

true... but it could be the fuel moving about in tank while accelerating that might move the float from being in and out of contact with the resistor fins... mine would read closer to accurate going down a hill or while under braking... its probably just bouncing in and out of contact with the fins... and he's probably associating speed with when it works/doesnt work...

Ok I see what your saying now and I haven't been that far into it yet but I'll try to this weekend. I'll see if I can give you more detail on what's going on. It doesn't matter if its full or empty,you have to drive it 4-5 miles at 55 or higher and when it starts working it will read fine until you let off the gas for more than 15 sec or so.I can drive around town all day and nothing,I hit the highway and it works,I've tried taking off fast up hill,down hill and nothing.I swear I'm not making this up its the weirdest crap I've ever seen.lol

I know it's an old thread, but my fuel gauge only works at a half tank... fill 'er up, sits way below empty until it gets to a half tank, then it reads normal. I mean, not a big deal, long as I know when I have to fill up again! But one of those little finicky things I'd like to fix. Figure it's that little tab in the sender?

Mine does exactly the same. It should be the same issue with the tab in the sender. From above 1/2 to full it is out of contact so it reads empty, but once it gets to 1/2 and below it is in contact and working. To be safe I've just been watching and resetting the trip meter at each fill up and ignoring the fuel gauge.

See