I have a 16oz injector which feeds perfectly at about 10psi below boiler pressure and downwards but won't pick up at boiler pressure (90psi) and just sends water through the overflow. At the last day out on Sunday some advice was to move the steam cone outwards and from others to move it inwards. Quite a conflict! Is it to do with the steam cone or something more deep seated? It's a Gordon Chiverton (sadly late) one. Thanks.

Thank you for your thoughts Luigi and Julian. I cleaned both injectors carefully before the run last Sunday and following Julian's suggestion re-checked the inlet pipework/valves but found nothing untoward. I have Gordon's injectors fitted to my other locos built over the last many years and have, I suppose, been 'feather-bedded' inasmuch as they have all just operated excellently and I haven't had to give a lot of thought about boiler feeding. The pair in question are possibly amongst the last made by Gordon. I have always dealt with him directly and have had many interesting chats with him about what you can and shouldn't do. I did call to ask him about the problem I had but he said that his failing health had caused him to abandon his business. It's the fact that they operate like all my other ones between 50 to 80 psi – they snap on and off and the overflow is dry – but at 90 (I've re-checked the gauge) a very wet overflow and a smidgeon into the boiler.