Fuel Sending Unit- A look Inside

[sean]

The original TankZilla units used this Saab fuel level sender...
http://www.redlinemotive.com/store/r...l+Sending+Unit
Attachment 3795

Since it reads in reverse from our senders, its not directly compatible with the stock gauge. TankZilla was a logic box that went between this sender and the gauge to correct those readings. TankZilla may not be available anymore, but this sender still has life for DeLoreans. I plan to make the new electronic instrument cluster fully compatible with this Saab unit, along will all DeLorean units available. A user-selectable jumper will switch between types.

Fuel level will be averaged over 30-60 seconds. No quick swings, no "clicks". Just averaged exact level.

Not available yet, but putting it out there as another option.

THANK YOU FOR THIS!!! I've had a used tankzilla on the shelf for a while, sender and ecu, but have never done anything with it yet b/c I wasnt sure the status of the sender

[stevedmc]

THANK YOU FOR THIS!!! I've had a used tankzilla on the shelf for a while, sender and ecu, but have never done anything with it yet b/c I wasnt sure the status of the sender

My TankZilla quit working about 18 months ago. Hopefully I didn't throw the thing away. If my DMCH unit ever fails it would be nice to couple the logic box with a new sender for less than $40 at my favorite auto parts store.

Thanks for the info.

[DMCH James]

The latest version of the DMC replacement fuel sender (marked with the letter "A" in the top housing) contains 12 reed switches and one reed switch for the low fuel light that are activated by the float. I had posted photos on the old DMCTalk (RIP). The fluctuations in fuel readings are caused by the fuel flowing quickly in and out of the sender tube. This can be compensated for by plugging the either of the two large holes on the bottom with a tight fitting screw. In some cases, we've filled BOTH and then drilled in 3/32 or smaller hole in the same general vicinity.

We've found that many of the units that when installed do not read "full" or not reading full for very long are simply a result of a combination of either the tank not being *completely* filled (which we don't like to recommend to prevent the boot popping off the top of the tank). Removing the sender from the tank, but leaving it connected and flipping it 180 degrees will show that it will read "full", but the shape of the tank, position of the sender, and the required location of the reed switches don't give the float enough travel to stay at the top switch for very long.

James

[Ron]

We've found that many of the units that when installed do not read "full" or not reading full for very long are simply a result of a combination of either the tank not being *completely* filled (which we don't like to recommend to prevent the boot popping off the top of the tank).

Might I suggest a resistor between the signal wire and ground? ..or is it off so far that it will lie (too much) on the empty end?

[sean]

The latest version of the DMC replacement fuel sender (marked with the letter "A" in the top housing)...

Has the height of the latest unit been shortened since the first run? Do owners of this new unit need to do anything for proper fitment? i.e. Loosen fuel tank closing plate bolts.

[Farrar]

Since Houston has released its new pump/sender all-in-one module, I was wondering if development on the Saab tank sender was going to proceed. For those of us not planning on using the new module, a separate tank level gauge sender will still be necessary.

Quick question: when you say "the sender reads in reverse" from ours, do you mean that its polarity is reversed? If memory serves, that can be easily cured with a single SPDT relay. Or is it something else?

My sending unit (Zilla) seems to be fine, but it never hurts to plan shead...

Thanks,
Farrar

[dmc6960]

I dont think anyone was proceeding on an independent project for the Saab sender. I was (and still am) planning to have it as a user-selectable setting for my electronic instrument cluster since it would be a very minor addition to the programming.

[Bitsyncmaster]

The original TankZilla units used this Saab fuel level sender...
http://www.redlinemotive.com/store/r...l+Sending+Unit
Attachment 3795

Since it reads in reverse from our senders, its not directly compatible with the stock gauge. TankZilla was a logic box that went between this sender and the gauge to correct those readings. TankZilla may not be available anymore, but this sender still has life for DeLoreans. I plan to make the new electronic instrument cluster fully compatible with this Saab unit, along will all DeLorean units available. A user-selectable jumper will switch between types.

Fuel level will be averaged over 30-60 seconds. No quick swings, no "clicks". Just averaged exact level.

Not available yet, but putting it out there as another option.

I have the Zilla unit and I'm happy with the way it works. I did have a few connection issues but those are solved. You will still see a little gauge movement when braking or acceleration but I expect that. Reversing the signal to work with our gauge would just take an op-amp and some resistors. Or better yet a micro could do everything an cure that minor movement.

[Ron]

Reversing the signal to work with our gauge would just take an op-amp and some resistors. Or better yet a micro could do everything an cure that minor movement.

THAT'S what I just couldn't remember to ask Sean about at the meet!...

I was looking at a LM107 OpAmp (with a 12V regulator, if needed) and then a 1NA117 Difference Mode Amplifier (Data Sheet Vo=V3-V2 ).
I wanted to measure the units resistance through its range if he still had it.
...Sean?

[Bitsyncmaster]

THAT'S what I just couldn't remember to ask Sean about at the meet!...

I was looking at a LM107 OpAmp (with a 12V regulator, if needed) and then a 1NA117 Difference Mode Amplifier (Data Sheet Vo=V3-V2 ).
I wanted to measure the units resistance through its range if he still had it.
...Sean?

Lots of opamps can run up to 30 volts but you need to see how much current the gauge takes (check resistance). My TankZilla electronis is potted so I could not see what they used. May also need a transistor to get higher current.