M42B18 - Lumpy Id

[Scottlaw]

Hello Zoners

Tearing my hair out with this one. Swapped my engine from a m40 to a m42.

All was going well and driving fine but then the car started to idle roughly, it almost splutters a tiny bit. It’s making the car shake a little with idle, but when it’s moving it’s great.

I have replaced:

- ICV (twice)
- intake boot
- vacuum connector thing
- spark plugs

Also ran multiple smoke tests with no results.

Any ideas would be appreciated!

Scott

[Speedtouch]

Has it got a standard ECU chip? 318is engines are very fickle when it comes to this!