Technical Fueltank size increase

[Bigbear52]

Hi all
I have a motorhome on a Fiat Ducato chassis and the fuel tank is 60 liters and would like to increase the tank to the full 90 liters
I have discovered that there is a plastic restrictor pipe inside the tank that when this is removed the tank will fill to the full 90 liters and looks a fairly simple job.
My question is how will this pipe removal affect the fuel gauge?
Can the fuel gauge be reset in the ECU to read 90 liters?
Do I need to buy a new fuel gauge?
Any infomation appreciated

 

[Abarthmultijet]

Hi, you can increase the via the ecu to let the ecu know the size is 90 liters. Can do it via MES.

Where did you find that you can remove the plastic restrictor pipe?

 

[Reg 65]

The vent pipe comes down from the top of the tank
When the fuel level reaches the bottom of the vent pipe, air can no longer escape so no more fuel can enter.
So adding extensions to the vent pipe reduces the capacity of the tank - to reduce tare weight and increase payload.
If you remove the vent pipe extension, the fuel gauge will simply ignore the top 30 litres in the 90 litre tank
So when you 30 litres in the 90 litre tank the gauge will show half full although its only one third full etc.
I have learned to live with this - you can still see when the fuel is getting low.
Everything is done through the larger of the 2 manhole covers in the cab floor.
So its theoretically an easy DIY job to take the top off the tank, remove the vent piper extension, and put it back
But you will need a tool to unscrew the big ring in the top of the tank (conventional thread turn anticlockwise to undo)
Because it sits in a recess so you can only reach it with your fingertips which won't be strong enough to undo it
You may also need a tool to squeeze the sides of the fuel pipe connectors to release them
You can get proper tools, but since we were only likely to need them once we bodged up a couple of tools - will try to post a photo of them
long nose pliers with the tips heated and bent in to squeeze and release fuel pipe connectors
Bit of flat bar bent into u shape and bolted to straight flat bar to use as a handle
The extension pipe removed - this extension is from a 75 litre tank so your 60 litre tank will have an extension about an inch longer.

 

[Reg 65]

I will try to post a photo of the professional tool for unscrewing the fuel tank top ring
Its better than mine because its shaped to fit around the ribs in the top ring
Reducing the risk of slipping off or cracking the ribs
But mine still worked
I have heard of people trying to unscrew the ring with hammer and blunt chisel.
This will almost certainly bust the ring because the angle of the chisel is restricted by the ring being down in the recess.

 

[Bigbear52]

Hi, you can increase the via the ecu to let the ecu know the size is 90 liters. Can do it via MES.

Where did you find that you can remove the plastic restrictor pipe?

Hi
Thanks for you reply
Could you explain MES a bit more please I have no idea what that is.
Restrictor removal from research on online

 

[Abarthmultijet]

Hi
Thanks for you reply
Could you explain MES a bit more please I have no idea what that is.
Restrictor removal from research on online

It is MultiECUscan, but after a bit of research you don't need it. What REG65 says. The measurement is wrong but you can live with this.
You can get an 90L fuel pump assembly so your measurement is ok. If you do that someone with a bit of experience with MultiECUscan can program the car thinking it has a 90L tank so the range on the dashboard is right.

 

[CheeseMonster]

I have converted my 60 litre to 90 litres. See this link which i used
https://www.reisemobiltreff.de/viewtopic.php?p=87936&hilit=60l+90l#p87936

The hardest bit is removing the sender unit to remove the tube. The torque is 75Nm from memory so needs a long extension.

I 3D printed a tool to make removing the tube easy, the .stl file is on the www or I can post it. It's still possible without the tool just not as easy.

The link explains the byte to change in the proxy file to correct the fuel gauge reading using MES. Or possibly less frightening is Alfaobd.

 

[Delta1944]

So I have carried out this fuel tank upgrade from 60l to 90l on my 2019 Ducato. All seemed ok. Went and filled to the new capacity, no problem, but now the on board display shows “the fuel level is unavailable”, the gauge is showing zero and the low level fuel light is flashing. Anyone else had this issue?

 

[Googlebot]

This might help.

Ducato Fuel Tank Size Increase

The owners hand book that came with Kon-Tiki Sport, say it has 75 litre tank(*) (*) A 90 litre tank is available on request for all versions. With the “ Tempo Libero” option a 60 litre tank is available on request. I think the option has to be ordered when the van is made, not an after market...

www.motorhomefun.co.uk

 

[BazeyUK]

HI, this is exactly what I would like to do with my van as it is restricted to 60 litre's.

As I don't have access to the software to make any changes, can you recommend who could help please?

 

[Reg 65]

So I have carried out this fuel tank upgrade from 60l to 90l on my 2019 Ducato. All seemed ok. Went and filled to the new capacity, no problem, but now the on board display shows “the fuel level is unavailable”, the gauge is showing zero and the low level fuel light is flashing. Anyone else had this issue?I think

Fuel guage and fuel light should be unaffected. You must have disturbed something when you took the sender unit out - is the connector back on properly? any wires pulled out?

 

[PL 8]

Fuel guage and fuel light should be unaffected. You must have disturbed something when you took the sender unit out - is the connector back on properly? any wires pulled out?

I have updated my 2021 with 75 l tank to 90 l. The only problem I have is that the fuel gage doesn´t start to move until I have used the first 15 l and that remaining km to drive says the same as fi it still has 75 l when it´s full.
But I did read a lot about this before updating the tank and read about different problems depending on the year of the car. So it´s no surprise to me that Delta1944 has the problem he mentions. I´ve read about different solutions both with mechanical changes and with multiecuscan and proxyalignement.