If its an intermittent problem (which it is) its hard to detect, best way would be to get a "known good" coil pack and when you have the problem swap it in with lets say number one cylinder, see if that improves, if not, swap back and try it then on number 2 cylinder - and so on. If you find that it makes no difference by the time you

 

Good idea Nigel I might give that a go.

I am right in thinking that the coilpack is those four black tubes underneath the coil cover which go down to the spark plugs?

 

Is this just when pulling away or when on VTEC too?

Is it running rich?

 

Only when pulling away. VTEC cross over is fine.
How can I tell if it's running rich?

 

You will smell it at idle, and you will lose about 30-50 miles from your normal fuel consumption per tank.

 

Fuel comsumption is about the same. 220-240 on a full tank
Since I've fitted my new Buddy Club exhaust and decat I do get a whiff of fuel, but I'm putting that down to the decat pipe. I couldn't smell that before these were fitted.

 

That all sounds fine, so rules out the lambda.

As long as nothing on the exhaust is leaking.

 

Novel way of putting it - but "yes" that is correct.