Smiths Fuel Sender Unit problems

[Geoff Deakin]

Hi All,

I am sooo close to putting my car back on the road after 18 months - In fact it MUST be back on the road next Friday 6th January for a geometry set up near here.

However, I'm having a problem with my new Smiths fuel gauge sender units.

The sender units were fitted in February, and there has been fuel in the tanks since then.

Now that all the electrics are working, I'm finding that both gauges read Full, even though the tanks are NOT full.

When I took the senders out of the tanks, I found they are covered with coarse white crystals - A bit like sea salt.

The garage is unheated with 4 to 7 degrees at the moment.

Would the crystals cause the problem? And what is the cure?

Hoping somebody out there can help.

Also having a problem with the speedo drive - See next thread.

Thanks in anticipation................and a Happy New Year to all.

Cheers,

Geoff.

 

[Seymour Snerd]

However, I'm having a problem with my new Smiths fuel gauge sender units.

The sender units were fitted in February, and there has been fuel in the tanks since then.

Now that all the electrics are working, I'm finding that both gauges read Full, even though the tanks are NOT full..

I don't remember if the sender in my Superformance is a smiths one, but they are all pretty similar. It has a wiper on a coil of wire so the resistance varies as the wiper moves over the coil. "Full" means the sender is showing very low resistance (~10 ohms or less). You can check this by putting an ohm meter across the sender leads. Possibly your white crystals have shorted the coil...???

I did a bunch of surgery on my sender described in this thread:

http://www.gt40s.com/forum/superfor...fuel-level-sender-calibration.html#post331669

You can probably take the sender apart and clean it.