2006 Corsa Twinport Misfiring Problem

[Par1]

I have a 2006 Corsa Twin Port. Over the last two month the car has started to intermittently misfire initially on 1 cylinder now on two cylinders. When it starts to misfire the engine management warning light appears.
A full diagnostic check carried out, only fault reported is the cylinder misfire. The coil pack has been changed, injectors swapped over and ultimately the ECU replaced but the car still intermittently misfires.
Does anyone have any suggestions to what the root cause could be and how to rectify the fault??

[andyiley]

Well it sounds like you may have covered sparks, but what about fuel?

Get the injectors off & get them tested/cleaned/refurbished.

Google injector cleaning & you will find someone who does it close to you.

[Jimmyarm]

Simple rules of misfire diagnostics;

Rule out spark issues
Rule out fuel issues

Then it becomes mechanical, valve or piston.

If you are confident in the electrical side of things then the cause must be a mechanical fault.

Cylinder leakdown test should show up an issue in this case.