lanbda sensor, on 316 but not on 318??

[dirtee-herbert]

Hello,
Just a quick question, i hope one of you can help me out please,

Im poping a M40B18 engine froma auto saloon in to a 316 touring,

The 316 touring has a labda sensor on the exhaust and the 318 saloon does not,

When i swap everything over ill be using the touring exhaust with the sensor in it along with the existing loom with the 318 engine and the 318 ECU.

My question is: will the lambda sensor actualy be doing anything when the swap is done or will i need a different ECU from a 318 that works with a lambda sensor if such a thing exists and if there are different ones etc.

Im bit of a noob! Thanks in advance

[Brianmoooore]

The ECU either needs the signal from a lambda sensor, or a fixed default signal, which is set by a potentiometer mounted on the air flow meter.
If you remove the bulkhead wiring covers on your cars, you will find, to the battery side of middle, a single pole plug and socket in a grey/black wire. This wire should be left disconnected on cars with a lambda sensor, but plugged together (connects the potentiometer) on cars without.

[dirtee-herbert]

Thank you Brianmooore, thats good.
Ill just use the 316 engine loom then,

Cheers

[Brianmoooore]

316i and 318i engine looms are identical, so it doesn't matter which you use, but, in either case, it the engine should be fitted with the loom already attached to it.
If you have a lambda sensor on the 316i exhaust, then it also has a cat., which will cost you a considerable amount in fuel consumption, so it's a good idea to either use the 318i non-cat. exhaust, or to knock the insides of the 316i cat. out with a steel rod.