Gas Gauge goes to E when I stop?

[iNFiNiTY125]

So what happens is unless my truck is completely full of gas whenever I stop the gauge it'll go down, after accelerate it'll go back up.

I'm wondering is it the sender unit or is it my gauge cluster? I can replace either, I'm leaning more towards the gauge cluster because my voltage meter also moves around, except it's just completely random it likes to stay at about 10V but when it feels like it it'll go up to 14.

I have another Fuel pump sender unit assembly but I believe it's different. came from a 91 it has the old-style cluster the moving Bar thing. I'm wondering if it would fit?

My truck is a 93 C2500 with a 350 tbi

The other unit came from a 91 K1500 with a 350tbi

Let me know what you guys think before i start changing parts out. thanks

 

[someotherguy]

The problem is more likely the tray inside the tank that the pump & float sits in, has broken loose from the bottom of the tank. The fasteners that hold it there eventually rust and let go. Doesn't happen a bunch, but it happens. This tray is sort of like a "reserve", not really, but what it does is protect the pump from starvation under maneuvering when the tank is getting low, and also helps to stabilize the gauge reading a bit. This was the design up until about mid-'97 on most fullsize GM truck models.

Richard

 

[gmcyukondriver]

Oh, mine has done the same thing for as long as I've been driving it (6 years).

Richard, is there any downside to this happening, or is there any way to fix it and make it so it won't happen again? I knew it was the float, but didn't know about the "tray" inside. I've never dropped my tank.

 

[someotherguy]

Eh, if the studs inside the tank rusted, it's kinda screwed as it can be difficult to get anything working in there to refasten the tray. I suppose if you cleaned the holy crap out of it you could attempt gluing the tray back down with JB or something like that but I wouldn't expect it to last.

I'd just be careful to not let it get down below 1/4 tank so you don't starve the pump as the fuel sloshes around. Surprised to hear you've never dropped the tank though - did the truck come with the Whipple on it? I thought TBI Whipple applications required replacing the fuel pump with the TPI unit or some other higher pressure piece.

Richard

 

[Horns]

Mine did that too. Vacuum leak.

~Via Mobile

 

[Cadon69]

Mine does it too. It drives me nuts sometimes LoL! Although I also have a weird thing I have a feeling is connected somehow. When the truck is cold and/or hasn't been run say over night or whatever. It takes a while to start. Once it's running and/or been running and them sits for up to a few hours it will start right up without even hesitating. I remember reading something somewhere it could be a leaking pickup tube. Basically instead of holding pressure in the line is leaks back into the tank. Then after a long time it has to turn over a while to get the fuel back to the tbi.


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[gmcyukondriver]

Eh, if the studs inside the tank rusted, it's kinda screwed as it can be difficult to get anything working in there to refasten the tray. I suppose if you cleaned the holy crap out of it you could attempt gluing the tray back down with JB or something like that but I wouldn't expect it to last.

I'd just be careful to not let it get down below 1/4 tank so you don't starve the pump as the fuel sloshes around. Surprised to hear you've never dropped the tank though - did the truck come with the Whipple on it? I thought TBI Whipple applications required replacing the fuel pump with the TPI unit or some other higher pressure piece.

Richard

Yeah, I usually don't let it get below 1/4 tank anyways.

The instructions I got said that 95's didn't need to do anything with the fuel pump. Not sure what changed between 94-95 (besides the interior and stuff, I know 95 was an oddball year). I'll probably be dropping the tank pretty soon anyways just to throw in a pump that I can be more confident in. I'll probably go with a TPI unit or a Walbro 255lph. When I do that, I'll take a look inside the tank and see if I think I could reattach that float and tray somehow.

 

[great white]

Fuel sending units are notorious for failing on these trucks when they get some are on them.

Everything from erratic behavior to dropping to zero.

 

[iNFiNiTY125]

Thanks for all the advise. I will look inside my tank soon and see how it looks

 

[Ladyzm18]

Any advise on gas gauge falling about half an inch past E when truck is off?


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