Pagoda SL Group

W113 Pagoda SL Group => Research & Development => Topic started by: stickandrudderman on August 30, 2024, 07:14:21

Title: Fuel tank sender
Post by: stickandrudderman on August 30, 2024, 07:14:21

I'm not an electronics expert by any stretch of the imagination but I have an idea....
Fuel level indications are rarely accurate; does anyone know how to install a transducer type sensor in the tank and convert the signal to be used by the gauge?

Title: Re: Fuel tank sender
Post by: mdsalemi on August 30, 2024, 12:12:47

Pretty much, most fuel tank senders are various kinds of float style, where the position of the float varies resistance.

However, there’s this: Holley 19-250 Easy Level™ Fuel Level sender that uses contactless lidar (laser imaging, detection, and ranging) for detecting fuel level.

Worth a shot to play with something like this in your shop…

Title: Re: Fuel tank sender
Post by: rwmastel on August 31, 2024, 03:17:26

Quote from: stickandrudderman on August 30, 2024, 07:14:21

Fuel level indications are rarely accurate

Rarely accurate??  I never felt my fuel guage was wrong, and my low fuel light seemed to come on at the appropriate level.

What level of accuracy are you looking for?Do you have a need to know if there is 10.2 liters in the tank vs 10.3 liters?

Title: Re: Fuel tank sender
Post by: johnk on August 31, 2024, 03:42:03

Mine is very inaccurate alway showing it being close to empty way too soon.

Title: Re: Fuel tank sender
Post by: rwmastel on August 31, 2024, 04:25:29

Maybe I'm lucky.  I would trust MB to provide a reasonably well engineered system, but maybe not durable over 5 decades.  Yours is inaccurate with good parts, good wiring, good grounds, etc?

Title: Re: Fuel tank sender
Post by: WRe on August 31, 2024, 07:08:13

Hi,
The fuel gauge is pretty accurate for me too. What can bother you is a dithering fuel needle, but this problem can be solved with an additional capacitor.
...WRe

Title: Re: Fuel tank sender
Post by: AdelaidePagoda on September 01, 2024, 16:56:02

My 230SL fuel tank is reasonable accurate although there are three things that those more knowledgeable on this site may be able to provide their expertise on:

1) The gauge flickers variably, usually when the car is mobile and more vigorously when the tank is above three quarter full. Any way to stop this?
2) The tank tends to drip petrol onto the rear bumper chrome when it is full and the car is in motion. It has an original full cap with the cork O ring. Aside from not filling the tank, any advice on how to stop it leaking?
3) The red light still comes on when the petrol tanks gets to the reserve fuel level. I am amazed this still works after 60 years. Anyone else reserve light still work?

Dave

Title: Re: Fuel tank sender
Post by: Pawel66 on September 01, 2024, 20:06:28

I would have thought:
ad. 1. You have the way to stop needle flickering described in the previous reply from WRe. It is about a capacitor soldered between the pins at the top of the fuel level sender.
ad. 2. I would suggest replacing the cork gasket on the fuel cap - a lot of discussions about it on the forum. The gasket is available from many vendors, including Mercedes.
ad. 3. Yes, it is fairly common that this light works, I think

Title: Re: Fuel tank sender
Post by: WRe on September 02, 2024, 06:21:56

Ad 1: See here https://www.sl113.org/wiki/Fuel/SenderUnit

Title: Re: Fuel tank sender
Post by: AdelaidePagoda on September 02, 2024, 20:51:27

Wonderful suggestions, as always. Noted and thanks.