Possible injector fault?

[Guy]

I'm sure most of you know I have a problem with misfiring and 'stumbling' at the moment. Cylinder 3 seems to flag most so I've just stripped it all and swapped coil packs 1 and 2 and coil packs 3 and 4 to see if the fault code changes from P303 to P304.

I'm now thinking it may be injector related. With the manifold off, you can look into each inlet port at the 2 inlet valves. On cylinders 1, 2 and 4, the inlet ports are immaculate. Port 3 has a weird blackish residue and some cream coloured residue all over the aluminium walls.

Could this be injector related? If it was a coil pack/ignition fault the visible evidence would be in the cylinder or exhaust manifold surely fwn.

 

[slamdunk]

where does the edr or piston blow-by flow back in? the inlets should all be clean???? That or you have burnt valve on no 3??????

Slam

 

[Guy]

The inlets were all spotless when I changed the sparks a couple of months ago. The case ventilation pipe enters at the far side of the manifold to the inlets. Why would a valve have burnt?

 

[Guy]

Been thinking about this and the symptoms point to head gasket leak or crack in the engine. Found an engine repair specialist in Stockport. Have to give them a bell in the morning...

 

[Vitus992]

Good luck chap - let us know how it goes.

 

[Guy]

Will do Daren. I really don't want to have to jib the car. I plan on being the first K12 to reach 250,000 miles .

 

[Guy]

Update: Just had it all apart again to get some pic's:

Clean cylinder inlet port:

Cylinder 3 inlet port:

Cylinder 3 plug is clean but slightly oily looking and not much sandy residue:

Going into Nissan tomorrow for them to have a look.