Fuel Gauge fluctuate

[MickHoolie]

Greetings All,

I have a 2000 XLS 2WD 4.0L 5-speed with a funky fuel gauge. On 3 occasions over the past year, I have been driving down the interstate with about 3/4 tank of gas and the gauge visibly begins to drop by more than a quarter tank. When I accelerate, the gauge returns to the correct level. This will continue this way for about 30 minutes before resuming normal operations.

The occurances have been months apart. I know how far I can drive on a tank so running out of fuel is not an issue...much. This is just an annoyance.

Has anyone else seen this and/or know what the cause/fix is?

Mick

 

[BrianDye]

Sounds like you could have a bad anti-slosh unit. (Dont know much about them, but if I had to guess, I would say thats a good place to start)

Its what basically makes your fuel gauge NOT bounce around while going up/down hills, accellerating/braking etc.

 

[MickHoolie]

I wouldn't say that it bounces, it just slowly drops until I get on the accelerator. When I back off, it begins to slowly drop again. Really, quite odd.

 

[Kevlar7R]

Perhaps an electrical issue? Most fuel gauges are a variable resistor, connected to a float. It sends a level signal by varying the voltage coming out. If the voltage going in is fluctuating, the voltage going out will be too. The fact that it picks up when you up the revs (and thereby uping the voltage output of the alternator) lends to this theory as well.

 

[jmoracco]

Your not alone with this issue, but im sure mine is due to movement of the gasoline on accel and braking. whether it is due to electrical malfunction and or mechanical failure, most likely a new sending/fuel pump unit would be in order. For me I will most likely wait till I need to replace fuel pump, but thats coming from someone who has already spent countless hours and bloody knuckles getting the whole timing components replaced....There is also some really good threads on fuel pump removal and replacement. Good luck

 

[AE86PandaDude]

maybe the explorer is saying that its not having fun right now and wants you to step on the gas and haul butt to wherever you are going.....

 

[MickHoolie]

My XLS has this happen only on rare occasions but my sister-in-law has the issue constantly. I will start checking out the anti slosh unit. I'm guessing that is the least expensive piece. Also, I will check the connections.

Thanks for all the input from everyone. I'll let you know what I find.

 

[firepop5]

I have a 96 5.0 V8. I started having this problem several years ago. Since a new fuel pump/sender unit was installed a few months before, (and I didn't want to drop the tank) I assumed the problem was electrical, the gauge or the anti-slosh unit. I went to a junk yard and inquired about an anti-slosh module. They would only sell me an entire cluster. I next went to the dealer and found you cannot buy the module alone, only a kit with a new fuel gauge, the a/s module, a new temp. gauge and a new temp. gauge sender. I was told a/s module and fuel gauge are calibrated to each other and must be changed together. The same for the temp gauge and sender. The kit cost $160. The 2 gauges came attached to a portion for the cluster. Alll went well until I tried to change the temp gauge sender. I cracked the lower intake manifold by cross threading the new sender. I can't post what came out of my mouth then. $800 later for a used manifold installed plus the $160 for the kit, the fuel gauge still acted like it was possessed!

Sorry for the long story, but looking back, I would leave it alone.

About a year later, the gauge started acting normally again!!!

Since then I've read that high sulphur content in certain brands of gasoline can cause a coating to form on the sender and cause the erratic behavior. They recommend several doses of Tech-ron fuel cleaner. I would try this and start buying another brand of gasoline.

 

[albeegood]

Sounds like you could have a bad anti-slosh unit. (Dont know much about them, but if I had to guess, I would say thats a good place to start)

Its what basically makes your fuel gauge NOT bounce around while going up/down hills, accellerating/braking etc.

I’m about to replace my anti slosh on my 98 explorer sport and would like to know if one from a 97 explorer fit? Thx.

 

[J_C]

^ You might pull the module out and examine it, might just need the contacts cleaned or have a solder joint crack, especially near where the larger resistor is in the corner.