Fiat Cinquecento injector light

[benny3008]

My fiat Cinquecento sporting 1.1's injector light keeps showing up when the car is idling or at low revs and I am fed up of trying to think of what it could be so am looking for suggestions. I have already replaced, ignition coils, spark plugs, ignition leads, fuel filter, lambda sensor and crank sensor. all pipes leading to the air intake system are intact and on correctly but there is an air flow regulator valve thing in a box on the air intake hose, its like a vacuum valve which I assume opens when at higher revs to allow more air through. this doesn't seem to return back to its original position once push closed which I think may be the issue but just wondering if anyone could shed some light. Should the valve be returning to its original position or is it solely reliant on air pressure to push it back? Reason I think this is the cause is because the injector light only comes on when the engine is at low revs, very rarely does it come on when over 2500 revs. Please can anyone help as i'm losing the will to live now, it has been on diagnostics twice now, once at a fiat specialist who have said no faults showed up. :-( It has also been struggling to start recently, it takes a very steady foot on the throttle to get it to fire into life.

[TWR]

If pos, try inserting WD40 Within the valve housing Benny.

[Toureman]

http://www.fiatforum.com/search.php?do=process