Gas Gauge / Intermittent Operation 355

Has the car been in storage or consistently used? Sometimes old fuel can affect sending unit operation and needs to be changed.

 

I dont have answer.. but I beleive this does/can happen.

my cousin has a 98 spider.. and he gets the same thing.. the gas gauge doesnt always work.

starts the car, gauge reads empty.. then can start it at a later point.. and it works.

 

The contacts on the floater are bad.

 

I have had the same problem with the fuel gauge. I machined a plug so the car could be used while repairing the sender. The float is attached to a spring type wire and can fail on the connection to the center slide shaft. Also, I noticed the float doesn't which may be effected by the ethanol our fuel. I soldered a connection and it failed again so I am working on a better solution. See pic. Senders were no longer available and last priced at $2k!

Jeff Pintler
89 348tb, 86tr, 99 360 3-pedal, S-160 bobcat
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Has anything come out of this work? My incoming 348 has a bad sender/float...

I was thinking of something from a marine type float might work instead, like: Liquid Sensors - Marine Diesel, Fuel, or Water Level Sensor

BTW, that sender is less than $50.

 

wither the sensor in the tank, the guage or the wiring.

What else could it be?

you need to check the connections wiggle some wires see if it comes back up if its not the wires, it probably the tank sensor float.

sometimes electrical parts don't work a good wack with a hammer to see if it works.

if it does well you know the problem.


But its impossible for us to troubleshoot over the internet, Just pointing you towards what it could be.

 

Mine was simply the gauge. It was sticky and intermittent. Also check wiring voltage and terminals on the connector.

 

Did you try pulling the gage cluster off and cleaning contacts? There are some tiny nuts on the back of gauges. Remove them clean them with an eraser and contact cleaner. This most often fixes problems. Always trouble shoot from the gauges back.

 

Let see.

Float is bad
Float connectors are not right
Float ECU is having fits
ECU Connectors are bad
Gauge is broken or sticky
Gauge electrical connectors are bad.

What else could it be?

 

The marine sensors might work. The drawing on the site implies there are magnetic reed switches with a magnet in the float. They certainly look robust enough. But 348 tanks have the mounting flange/wire connections on the bottom of the tank so the seal has to be good. Also, the drawing does not show a contact for the low fuel warning lamp for the instrument cluster. The second pic that I posted has the gray shaft inverted and the tight spiral wire attaches to the embedded coil on the shaft. The low fuel lamp uses the metal ring on the bottom of the float to short to the "tight spiral wire". I found two problems in my fuel sender: the float doesn't float very well and of course, the broken wire connection. I found float material called Nitrophyl (sp?) that many senders use and bought a chunk to machine and I figured out a nylon piece to eliminate the high strain wire connection. It is very easy to machine a blanking plug to remove the sender and still use the car. A simple disc of aluminum leaks because the gasket doesn't stay centered. Also, you need to make a tool to un-screw the sealing ring on the sender. Lastly, there in no ECU for the fuel gauge. As much as I would love to get back to this project, a 911 that was worked on by clowns is taking all my time. FWIW.

Jeff Pintler
89 34tb, 86tr, 99 360 3-pedal, S-160 bobcat