have a look at this post i found
I cleaned mine about 3 months ago after getting a how to from a vx mechanic friend of mine. I cleaned up the solenoid side and re greased and cleaned out the spring side with carb cleaner. It was running fine until about a month ago when the symptoms changed. My car started to judder a around 2000 and then 2500 rpm but only when accelerating slowly through the rev range. It was as though there was a misfire. Reading though our the forum it seemed as though it was the old 'injector No 3' wiring issue which a replaced a couple of weeks ago but this didn't fix the problem. The other thing i found herre was a possible injector problem but before I spent a few hundred quid on an injector I thought i'd check the EGR again. I discovered that the 'spring' side was sticking very slightly when depressed. It just didn't seem completely smooth, so, I cleaned it out again and greased the sleave that the bar runs through...... Success!! did this yesterday and my car is running smooth as kojaks head again!!