Are all the fuel pumps the same for different engine sizes?

[mull3tt]

Are all the fuel pumps the same for different engine sizes? i.e. will a 320 one fit on a 318 lux?

[Brianmoooore]

The basic pump is the same, but there are two different mounting brackets. The pump can be changed between brackets if necessary, and just involves soldering two wires.
The difference between the brackets is that some have two pipe connections and others only one.
You can use a two pipe pump in place of a single pipe one by blocking the spare connection with a short piece of fuel hose and a plug of some kind.
If you want to use a single pipe pump in place of a two pipe, then the original bracket must be used and the pump swapped.

[gareth]

brian, out of curiosity, do you know if a 2 pipe pump be the type fitted to a 318is? i only ask as me, martin (driftboy) and theo (theo325) were a bit puzzled when we found 3 fuel lines on theos 318is when dropping a M30 in the other day. though it seems only one is a pressurised feed and it fired up ok.

sorry for the off topic btw...

[Brianmoooore]

Can't remember off hand whats in the iS, but there are three fuel lines on all facelift E30s.
One is the pressurised feed line, one is the fuel tank vent, and the third is the excess fuel return line from the pressure regulator to the tank. This either goes into the tank via a stub pipe on the tank, or by the second connection on the fuel pump.

[mull3tt]

The basic pump is the same, but there are two different mounting brackets. The pump can be changed between brackets if necessary, and just involves soldering two wires.
The difference between the brackets is that some have two pipe connections and others only one.
You can use a two pipe pump in place of a single pipe one by blocking the spare connection with a short piece of fuel hose and a plug of some kind.
If you want to use a single pipe pump in place of a two pipe, then the original bracket must be used and the pump swapped.

So if i bought a pump from a 320 for my 318i, i could block 1 of the pipes on the pump and keep it in the car as a spare?

[Brianmoooore]

So if i bought a pump from a 320 for my 318i, i could block 1 of the pipes on the pump and keep it in the car as a spare?

correct!

[mull3tt]

Cool, thanks for the help

[gareth]

so where would the breather connect to? we were thinking into the manifold or something so it sucks up fumes but i've never seen it connected to anything.

[Brianmoooore]

so where would the breather connect to? we were thinking into the manifold or something so it sucks up fumes but i've never seen it connected to anything.

Breather pipe does connect to the inlet manifold on emissions equipped cars - via a carbon canister and a solenoid valve.
On most E30s the end just tucks into the reinforcement structure for the LH suspension turret.

[gareth]

cheers brian!

that's another pint i owe you! well, actually i'll add that to theos tab!

[Ziggy]

Worth mentioning that early cars had a 2-pump setup?

[Theo]

Mystery solved then, there was a bit of head scratching when we were confronted by 3 fuel lines! I've noticed that the engine bay smells of petrol fumes a little, seems odd that it's simply vented to the atmosphere.

Thanks for the info Brain, and cheers for looking into it Gareth.

[Brianmoooore]

I've noticed that the engine bay smells of petrol fumes a little, seems odd that it's simply vented to the atmosphere.

If you can smell fuel under the bonnet, I very much doubt that it's from the vent pipe.
Far more likely to be a weeping high pressure hose. Check them out ASAP!

[Brianmoooore]

Worth mentioning that early cars had a 2-pump setup?

This is easily replaced by a single in tank pump as well!

[gareth]

Worth mentioning that early cars had a 2-pump setup?

This is easily replaced by a single in tank pump as well!

which will yield a handy spare inline pump for syphoning out fuel etc!

[oze30]

Are the pumps the same output/flow rate from m20 to m30?