tickover

[Dave Wilkinson]

Kevin, The usual culprit here is the Idle Stabilation Valve. It's a small cylindrical "thingy" right on top of the inlet manifold, dead centre above the engine. It's an electrically operated valve that bleeds air to the inlet manifold when the engine is on idle. It's operated by the DME directly and is driven by pulses to achieve very small movements in quick response to the engine conditions. A common problem is that the all-too-often oil overfills can result in excessive oil mist being recycled to the inlet manifold which in turn accumulates in the ISV and makes it "sticky". If you remove the ISV and clean it out - carefully - with some brake cleaner I suspect your problem may be solved. If your problem is more specifically experienced when the engine is only cold it's possible that you could have aproblem with the cylinder head temperature sensor. This tells the DME that the engine is cold and the DME effectively engages the "choke". No sensor means no choke and the engine will not reliably idle until it's warm. Hope that helps. Regards Dave

 

[turnerkl]

thanks dave, car has just been serviced so the oil issue sounds possible, however just taken it for a longer run and seems to be better when properly warm -so could still be either! will have a look at the stabilisation valve first thanks

 

[turnerkl]

i'm sure i've seen this issue posted before so apologies if i'm going over old ground. My engine has just started to stall on tickover, particularly when engine is not upto full temperature. Not all the time but when it's not stalling the tickover is very lumpy, droping to 500rpm and then upto 1000rpm. Hopefully nothing serious but as usual any thoughts welcome