Fuel tanks

[bimanut]

The petrol tank on my car is all rusted up round the inlet stub.
This tank has a connecting pipe between the two parts of the tank.
`89 318i 2dr

I`ve got a spare one i removed from a `91 318 cab,but it has a bigger compartment on the left side and no joining pipe between the two compartments.
What i want to know is can i use this tank to replace the other one and is it a straight swap?

[Grrrmachine]

The tank itself is a straight swap, but it sounds like you're swapping a 55L for a 63L, and that will mean changing your gauges and adding another sender:

http://www.e30zone.net/e30zonewiki/inde ... #Fuel_Tank

[bimanut]

Thanks.
I`ve got everything that was on the cab so clocks can be swapped,sender unit and pump is still in replacement tank.So after reading the wiki i think its a straight swap.
Need to read the bit about the fuel pump again cuz its not sinking in

[Brianmoooore]

You'll need to modify the level sender wiring to accommodate the second sender (change the whole rear loom that plugs into the socket at the RH side of the rear seat is preferable. Link the pad sensor wires as on the existing rear loom if you don't have rear discs.)
The instrument cluster, or at least the fuel gauge will need changing, and the fuel return pipe must be connected to the stub on then RH side of the new tank, or you won't be able to use the fuel in the RH side.
If you use your existing fuel pump, with two pipes, the return pipe must be blocked off, by attaching a short length of fuel hose and plugging the end.

[DanThe]

Second sensor wiring is as simple as cutting one wire and making two joints to it, I wouldnt be changing the loom unless it was an early car with no fuel pump wiring

[bimanut]

Nothing runs simple does it lol.

Ye i know that i will have to move the return line.

Would rather splice a couple of wires than change the loom.Do you know what colour wire i`ll have to splice dan

[Brianmoooore]

Changing the loom is a five minute job if the tank is out and you have access under the car.
However, if you want to splice wires, you cut the brown/green going to the sender in the fuel pump assembly, then extend both cut ends to the sender on the LH side.