Cold Idle Problems

[Baconer]

Since i purchased the car last year it has always had idle problems (it would idle at around 1200-1500 cold or warm which i later found was caused by the climate control unit being stuck 'on') so i cleaned the AAC valve and reset the idle (long way) and the problem was solved. So anyway the car has run perfectly for the past month with no problems until a few days ago when the car stalled on idle when started cold in the morning and since then has been an absolute pig on idle, the car shakes enough to move you in your seat but is fine once it reaches operating temp... I have cleaned the AAC, reset the idle, checked for vacuum leaks (there was 1 split pipe but thats now fixed, didnt fix idle though) and tested without O2 plugged in.

Some other things that might be linked to the problem, I have an Apexi turbo timer and the O2 reads 0.00V on idle but goes back to normal scanning (0.1-0.6V) when in gear. The car stops its weird shaking above 2000rpm even when cold. The exhaust smells like straight petrol when idling while cold but fixes when it reaches operating temp. Finally, what tells me it has to do with whatever controls the cold start operation of the car is the second it reaches the standard operating temp the car jolts, revs drop to around 800-900, shaking stops and everything goes quiet and the car absolutely purrs...

Car is a completely stock standard Series 2 R33, no exhaust mods, no ecu changes, straight from the factory R33.

Please help :X

[Baconer]

any ideas, i dont know much (nothing) about how the car handles or acts differently when cold started. Am i better off just going to a mechanic?

[MBS206]

What revs does it sit at when cold?

It could quite be that your cold start valve isn't working properly. And by the sounds of it, a heap of fuel is being dumped in, and the valve is opened, hence, lots of fuel, rich and rough.

[Baconer]

it idles around 1500 when cold

[WogsRus]

coild be the cold start valve under the intake manifold

[Baconer]

What about it would be causing it?

Dirt/grime buildup or is the valve just past its used by date?