Engine Worries

[BiggestNizzy]

Update

Today I stripped out the throttle body and AICV gave everything a clean up (that plastic throttle body will have to go it's looks crap) and I found a light oily substance inside the plenum is this normal ? I can't see it being normal but I know nothing this sort of thing. I did wonder if it was oil from the air filter but there was nothing in the connecting pipe from the airbox.

I havn't had a chance to see if it's sorted the bouncy idle (it was bad this morning).

[robin]

The oil will be coming from one or both of the breathers that connect the intake manifold to the cam cover. Excessive oil here can be caused by crank case pressurisation which in turn is generally caused by either a hole in the piston or more likely worn pistons/rings. However, there is always some oil travelling this way (when you go from open throttle to closed throttle the manifold drops from atmospheric pressure to a vacuum - it will pull in oil vapour from the cam cover as it does this). There should be a wire-wool oil trap in the cam cover where the breather joins the cover - it's worth poppping the cam cover off and checking that the wire-wool filter is still there and hasn't shifted to allow easier oil egress.

A compression test might also be in order.

If your idle is really erratic I'm afraid to say it could be down to the cams you are running - the MEMS might struggle with them. A partial fix is to try and restrict the airflow into the IACV (thus making it a less sensitive device - if you know you're feedback loops, you're reducing the error gain ) by either inserting some sort of collar into the pipe or perhaps crimping the pipe up a bit to restrict airflow.

If this doesn't work for you then swapping cams isn't too hard, though of course you'll lose a pony or two.

Cheers,
Robin