Fuel level doesnt stop moving ...

[inno87]

in my old zetec the gauge was accurate and didnt move rapidly. in my new-ish one it moves constantly and on turns the needle moves from 3/4 to full and when i go the other way i could reach a half. what the ... i have no idea, and its pissing me off. i have read other posts but they dont anser my question. what could it be?

 

[greasemonkey1489]

The readings are up and down because the fuel is sloshing around in your tank and the sender consists of a little float that changes height in the tank with the fuel level. Most times, the needle mechanism is supposed to move slowly so you dont get a changing level every second. It may be worn or malfunctioning in your guage cluster or the sender on the fuel pump is broken. (hopefully not the second one)

 

[inno87]

so how can i go about this. what should i do to start finding out what the problem is.

how do i see if its the fuel sender?

how do i see if its the gauge?

 

[Silver Bullet]

so how can i go about this. what should i do to start finding out what the problem is.

how do i see if its the fuel sender?

how do i see if its the gauge?

Can't be the sender, even if sending unit was bad guage should still buffer bad readings and not move fast. Basically guage is designed to move slowly so you don't see these quick changes. Same for the temp guage, you don't think your engine temp is really that steady do you. Mine gets up to temp and then doesn't even move a micro inch.

For a non technical way to check your guage do this. Next time at gas station leave you ignition on when filling gas. Watch gas guage and if it starts moving immediately and very fast in one direction only then your guage is toast. It should crawl up to full position and lag behind the pump (i.e. when tank full and pumps shuts off your guage will not yet be at full)

 

[Brent372]

Go to a junkyard and get a new gauge cluster... or find somebody on here nearby you and swap with them for a day. Does the problem follow the car or the cluster?