308 Fuel Level Sending Unit

The PO of my '85 QV replaced the sending unit, and the old part looks exactly like 308gtsqv's. His shop put in a "Ferrari specific aftermarket unit (from Ferrari)" and range is way off. It takes 3-4 gallons before gauge comes off full, and tank is empty when gauge reads 40%. I'm new at this area, so appreciate some help:

- might my issue be the gauge, not the sender?
- if my issue is an incorrect replacement sending unit, can someone list the part number and source(s) for the acceptable Fiat part? Will it need mods like pad did to his Ricambi part? (I do have a price request in to Tom Vail for part MC3701100.)

Thank you.

 

Sounds like it could be as simple as adjusting the angle of the float . You will need to remove it anyway so check the impedance range with an ohm meter while its out.


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This is exactly what happened with my car. The previous owner had let the car sit too long and the sending unit corroded and clogged the tank. When an attempt was made to start the car it sucked the junk through the fuel pump and accumulator. Which then left the car sitting for a few more years. I'm having to rebuild the whole fuel system now. Every piece of the fuel system, component, rubber hose, and metal lines, have been removed and are being cleaned and/or replaced.

I want to rebuild the original sending unit. Does anyone know if that main shaft is anodized? My plan is to completely disassemble it and rebuild it from square one. ( I know, a glutton for punishment). Any help would be appreciated. I don't believe a factory original is still available.

One other thing, I see in the literature that there is supposed to be an in-tank filter just inside of the main outlet/fuel pump hose connector. Mine seems to be a straight through pipe. Or is it that the "pipe" is more of an open ended screen inside the tank? Anyone ever pulled there's out? I've attempted to remove mine but need to let it sit for a few more days after hitting it with PB Blaster.
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ValentinoQV, here's a picture of my original filter from my '85 QV. It is an "exploded view" as it is the way it was found when my tank was being repaired! There are probably parts diagrams and others with better pictures but hope this helps.
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To install the replacement unit, it needs to be bent/cut to exactly match the old unit. Specifically, the down shaft (threaded bar) needs to be bent towards to the left and the float arm needs to be bent/cut to match the original. If you just drop in the new unit, the float arm with hang up on the baffle and the gauge will be stuck at Full.

 

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Has anyone removed the rivets and removed this mounting ring? My driver-side tank needs a refresh.

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I read that MEK can clean up this junk and varnish inside the tank.

 

I need to do this too, thanks, I'll be watching closely.

 

I found a vendor for the universal fuel sender....

https://www.si-parts.com/en/senders/12425-fuel-level-sender_29-240-000.html

COBO universal fuel sender 29240000 or 1029372

I tried ordering a unit but cannot complete the order on their website. I am attempting again to inquire for help (no luck last time). Does anyone know where this unit is available on an international parts store website? Not sure what Fiat model would also use this unit. I am aware of the availability at our Ferrari parts vendors, and I may be chasing only a few dollars in savings.



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Original sender units for our old cars are NLA components as I'm aware. Here is how I installed a aftermarket model in my BBi. Note that it can take some trial and error to adjust the float pin for optimum gauge reading as discussed above

https://www.ferrarichat.com/forum/posts/146968292/

Best, Peter

 

Excellent, Peter! I usually pride myself on recognizing most of the 308 posts from the last 20 years....but there is a lot of transferable knowledge in the Boxer section and your post! I got homework to do.
Superformance seems to have the best price for this sender unit.