fuel guage hepl
 

I have an 89 formula 357 the fuel guage is stuck on full
I checked my connections at the sending unit and they are connected tight and free of corrosion and all that bad stuff. tried find a sending unit and haven't had any luck anyone have any suggestions?

ddabal
 

Hi
mine is an 87, so I don't know if they use the same unit. changed mine last year. original was a VDO. I Got the same one online, works fine. theyr good units but a little more expensive than the universal ones.
pull the old sending unit out to get the correct length. they cant be cut or changed. easy enough.

hope this helps

Yes, get the number off your current sending unit . . . Should be visible on the outer portion. The sending units are the tube type.

The gauge is probably not compatible with generic sending units . . . Different resistance range, so make sure to get a VDO unit. They are readily available and have not changed much over the years. Still very common in all kinds of machinery, equipment, boats, cars, etc.

ya that was my problem I got the number off of it and tried to find one and couldn't ill try again and see what I can come up with but had no luck last year I just filled it up every time I used it last year the guy I bought it from putt nicer gauges in it is there a way to test sending unit id hate to spend the money replacing it when its not the sending unit

ddabal
 

First off check to make sure its a VDO, it might have been replaced with a generic/different brand by a previous owner. Is the gauge VDO? the VDO is a straight cylindrical tube about an
1 1/4" or so in diameter. no visible floats or arms on it.
have you taken it out, the number may be on the underside. if it is a VDO and you cant find the number just go online and get the correct length, you should be fine. if its not VDO and the gauge is, just measure the depth of the tank where the unit goes in and buy the closest one to that depth. it should work fine.
Just a note, the VDO GAUGE has a small hole in it to adjust the setting, it should tell you on the instructions. you may/may not have to tweak it a bit to get it to read the way you want. I had to do mine when I ran out of gas when gauge read just under 1/4. YOU CANT ADJUST THE SENDING UNIT. that's why its important you get the correct length.
hope this helps

ddabal

I have livorsi gauges in this boat could that be an issue

Disconnect the wire from the sending unit to the gauge... Does the gauge go to empty?
If it goes to empty you know its right at the sending unit, it could be the wrong one or stuck/broken

You can take a Volt Ohm Meter and measure the resistance of the sending unit. Go for a ride and burn off a 1/4 tank ish of gas. Remeasure the sending unit resistance... If the mesurements stay the same its stuck/broken. if they change, Then pull the sending unit to see if its the right one.

I had the same problem, bought a gaffrig tube sender and I had a livorsi gage....works fine now, gaffrig sender was cheaper than livorsi and gaffrig pre set the tube for me

I am kind of dealing with the same problem myself, I have VDO gauges also, after I run it for a a couple hours the gauge will just start to bounce off full to 3/4 when underway and when I go to top it off it takes about 25-30 gallons..... is this something that can be adjusted

ttt