Check ePer for compatability, check FIAT UK for recall (have your VIN and registration number to hand.

Not sure about compatability. The SPI system is return, the MPI non return, and the pumps are different.

Thanks for info. I'm not replacing pump only tank. All the tanks on ebay give the SPI code only but all say this is correct for ALL the 1108cc cars.
Other threads on forum seem to agree that the tanks are the same?
I can't actuall see any evidence that tank is leaking.
It's my son's car and he was driving around for a week with fuel cap undone! I reckon fuel spilt out and run down tank. I'm going to ask MOT man to show me the 'corroded' area as tank looks like new to me.

For the seicento, I could be wrong, i think all the fuel tank is the same regardless if is SPI or MPI.

Ming

Usually they leak at the seam (towards the top).

From (distant) memory, the studs which hold the pumps in are different spacings, so you may need to swap the pump internals over (and/or do some nifty welding).

fingers99 said:

Usually they leak at the seam (towards the top).

From (distant) memory, the studs which hold the pumps in are different spacings, so you may need to swap the pump internals over (and/or do some nifty welding).

Click to expand...

The mounting differ between cinq and sei, i don't think it differ between different sei models.

fingers99 said:

Usually they leak at the seam (towards the top).

From (distant) memory, the studs which hold the pumps in are different spacings, so you may need to swap the pump internals over (and/or do some nifty welding).

Click to expand...

Fingers is right, Cinquecento fuel pump / sender units have different numbers of studs compared to the Seicento tanks ( that hold the sender pump unit in place ) also the fuel connections and wire connectors are different.

Ive broken many Cinqs and Sei's.

The actual mounting of the tank is the same for each model.

Cento Painter said:

Fingers is right, Cinquecento fuel pump / sender units have different numbers of studs compared to the Seicento tanks ( that hold the sender pump unit in place ) also the fuel connections and wire connectors are different.

Ive broken many Cinqs and Sei's.

The actual mounting of the tank is the same for each model.

Click to expand...

Yeah, but do you know if Sei have 2 different mounting of the pumps between SPI and MPI?

Ming

I can tell you that the SEI spi is different to a Spi Cinq, but i dont ahve any Sei Mpi tanks at the moment to compare it too. If someone wants to post a pic of an Mpi ( top of the tank , under the inspection plate ) i can tell you.

Something i want to find out too, and i assume this is what the OP is asking.

Ming

ycming said:

Yeah, but do you know if Sei have 2 different mounting of the pumps between SPI and MPI?

Ming

Click to expand...

Pretty sure they do. (Else why the different part numbers?) But can't remember when (or why) I tried it!

Is it the fact that one has only One Breather and the other has Two ?

No -- or, at least, not that I remember. From memory, the return is part of the pump.

My guess -- and it really is nothing more -- is that you could either cut the old tank's pump fixing ring out and weld it to the new tank, or fit the working components out of an MPI pump into the housing of an SPI one.

But it's only a guess.

The obvious, apparent from the literature, differences are return vs non return, and 1.2(?) bar vs 3 bar nominal pressure.

Big Mick at eurocarcare might know. Or maybe jiminwatford has one of each, side by side?

Seicento Spi tank can be fitted to Mpi. The breather stub is different but you can get the convoluted tube to go over.
The filler inlet tubes are slightly different in design and diameter.
More pics in my gallery.