lotus fuel gauge

[lotus 30]

Electronics not my strong point i have a lotus excel and the fuel gauge dances about as the sender moves with the fuel sloshing about in the tank. The damping on the gauge has gone out the window. My question is will this resister on the fuel gauge damp the input voltage and slow the needle down i was wondering if it has failed and how do i test it Andy

 

[pedrobedro]

Youtube is your guide

 

[RonA]

If your Lotus is anything like the one I owned nearly 30 years ago, very few parts on the car are made by Lotus.
Your gauge is probably off some other vehicle & the resistor added to get the calibration right for your tank.
Baffling in the tank is meant to stop fuel sloshing about but your stuck with what Lotus designed in.
No expert but perhaps a small capacitor between the gauge & earth might damp it down
RonA

 

[voipio]

I would suggest quite a large capacitor would be necessary. At least 10,000uF, and probably 100,000uF to smooth out the fluctuations.

 

[RonA]

I would suggest quite a large capacitor would be necessary. At least 10,000uF, and probably 100,000uF to smooth out the fluctuations.

Sounds like you may have previous experience in such matters. Presumably working voltage would be need to be greater than 12v, would the capacitor need to be polarised?
RonA

 

[Screwdriver]

Electronics not my strong point i have a lotus excel and the fuel gauge dances about as the sender moves with the fuel sloshing about in the tank. The damping on the gauge has gone out the window. My question is will this resister on the fuel gauge damp the input voltage and slow the needle down i was wondering if it has failed and how do i test it AndyView attachment 311637

I would be looking for a modern unit and keep the old original one for sentimental reasons (or just to keep the thing original for resale).

Worst case scenario: bad wiring anywhere near fuel (or anywhere near a Lotus tbh).

A modern fuel gauge might be solid state or optical and all you need to do is hook it up to the gauge and calibrate.

 

[lotus 30]

Trying to sort it and understand what is going on its fun the kids on the excel forum just say they are all like it i have had the car from new 1991 so i know it used to work fine just going through the instructions (w/shop manual) thats a first LOL. trying to find a voltage regulator or something similar which has failed. or is the gauge got it in already hence the picture and looking for advice as stated i know nothing about electronics but on here is a wealth of knowledge i have a spare sender unit going into the w/shop rig up a test rig thank you all for going to the trouble of replying andy

 

[badabec]

The voltage regulator is a little tin can about 1 1/4 inches x 5/8th inches and 1/2 inch deep. Usually stuck to the dashboard.
Possibly

 

[lotus 30]

The voltage regulator is a little tin can about 1 1/4 inches x 5/8th inches and 1/2 inch deep. Usually stuck to the dashboard.
Possibly

That is how it used to be but there is no voltage control in there first thing i thought about that is why i am thinking it is built in the gauge it looks very complex bit of kit not just a moving coil as the old stuff .

 

[lotus 30]

got my answer thanks everyone for the input
Hi Andy,

Yes it is a wire wound 68 ohm resistor and would have a damping effect. Ensure the tank is well grounded and the float is not perforated.

Tom

 

[KemppiFrog]

Back when we did stuff for them...Colin's only reason to sell road cars was to continue racing, and it showed in the production processes. Much later, finding which bits were used for your car was a bit of a minefield, back calipers come to mind...