Fuel sender replacement

[PeterBiggerstaff]

Hi Everybody!

Due to ordering parts from the USA being much more of a hassle than I thought it would be, I'm going to try and source as many parts locally (New Zealand) as I can.

Does anyone have the specs (voltage range etc) for the Fuel sender? mine has completely rotted away, all that was left was the empty case and some wires, the rest was spread around the tank all broken up.

If I can find either the specs or a cross-reference replacement, that would be awesome.

[Denverdelorean]

Hi Everybody!

Due to ordering parts from the USA being much more of a hassle than I thought it would be, I'm going to try and source as many parts locally (New Zealand) as I can.

Does anyone have the specs (voltage range etc) for the Fuel sender? mine has completely rotted away, all that was left was the empty case and some wires, the rest was spread around the tank all broken up.

If I can find either the specs or a cross-reference replacement, that would be awesome.

I believe the one hervey sells is made from these moeller marine units. not sure if that would be easier to source locally or not.

here is a thread on DMC today.
http://www.dmctoday.com/showthread.php?908-Wanted-Fuel-Pump-Sender-and-Fuel-Pump-Boot

[DMCMW Dave]

The biggest problem with cross-referencing the fuel senders is that the resistance in the DMC unit is backwards from what is "normal" for other cars. This is why the old Zilla unit and the current DMCH all-in-one unit have an extra box of electronics to turn it around. The DMCH box also damps the signal quite a bit, not sure about the Zilla.

I've seen a car or two with a cross-ref unit that worked fine - other than the fact that an empty tank read full and a full tank read empty.

The later float-type units are made with the resistance going the right way. What you see on the S-T unit is the same as what's inside the DMCH/DMCEU unit, but without that outer cover the float will move very quickly as the fuel sloshes, so the gauge will jump all over the place as the car moves. It will work fine with the car sitting still.

[PeterBiggerstaff]

Thanks again guys, you have given me some food for thought :)

[Denverdelorean]

Thanks again guys, you have given me some food for thought :)

Dave is correct, my fuel level looks like it jumps all over the place. it's only right at long red lights :-)

[PeterBiggerstaff]

Ok, so after a lot of digging and research, I think I have found one that will work:

http://www.capitalcivic.co.nz/product_detail.php?part_no=48-323132

The specs are:
Empty Ohms: 240
Full Ohms: 30
Tube Length: 200mm

The length should be fine, and the oms are in the right range, but are they the right way around?

I don't mind my gauge being 'upside down' if need be I can get a PIC and write some firmware to flip it around at some stage, I just want to get my poor car running!

[DMCMW Dave]

Ok, so after a lot of digging and research, I think I have found one that will work:

http://www.capitalcivic.co.nz/product_detail.php?part_no=48-323132

The specs are:
Empty Ohms: 240
Full Ohms: 30
Tube Length: 200mm

The length should be fine, and the oms are in the right range, but are they the right way around?

I don't mind my gauge being 'upside down' if need be I can get a PIC and write some firmware to flip it around at some stage, I just want to get my poor car running!

I just measured a random one here and it appears that empty is about 30 and full is about 220. Approximate.

[PeterBiggerstaff]

Thanks Dave, much appreciated!

[Flash66]

I don't mind my gauge being 'upside down' if need be I can get a PIC and write some firmware to flip it around at some stage, I just want to get my poor car running!

Could probably just use a 7404 inverter.

[Bitsyncmaster]

Could probably just use a 7404 inverter.

That inverter is for digital logic. You would need an op-amp wired in inverting mode. Or a micro can do it in software.

[Flash66]

Haha! I don't know what I was thinking. I just did something similar with an Atmel a few months ago.

[Delorean Industries]

We avoid the box solution completely by simply inverting the potentiometer on the pump housing. The only box in our system is for the low fuel light calibration. This allows for owners to set when the light will trigger.