Hi, i've been looking at my zaf gsi today as all of a sudden its developed a terrible missfire. It idles ok but as soon as the revs climb above 2000RPM it misses quite badly. Compression on the engine is good and no play in turbo.
Cleaned up the plugs which were black with soot and replaced air filter. No improvement and plugs covered in soot again after running for a short time.
Firstly is there an egr on the z20let as it appears to be fueling heavy as plugs so black?
If not could the coil pack cause this problem or would it be missing at idle too?
Any help to point me in the right direction or rule anything out much appreciated.
Also checked for fault codes and shows none.