Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

Looks like the rear bank was flooded with water in the past.

Used endoscope for further inspection.

Even with this terrible looking, no misfire.











Having said this, at some point in the past, wrong spec top terminal was in use with the spark plug.

The centre spring loaded terminal of the IG coil was already damaged/worn and had to be replaced.










Replaced all three rear bank IG coils with the UF91.

As the standard procedure, treated with the silicone compound.










New NGK spark plugs.

There is no benefit from the point of performance and cost effectiveness in using the likes of the iridium, etc plugs over the OEM specified NGK PFR6G-11 (pre-OBD2)
unless you have modifications requiring the extra spark energy.


Took compression data in 5 rounds and happy with the result.