Thanks for the reply's guys. kosienutter - yes it is a 4x4 and yes those are the plugs. I had also hard wired out one of the plugs many years ago but when I recently took the head off I found it much easier to recut this connection rather than removing all the loom from the engine. When reassembling I redid this plug with a new sealed Deutsch
type plug and socket and am also intending to do the other two to hopefully get rid of an intermittant miss that I get particularly when cold. The symptoms are a loss of the CPS signal (tacho dropping ) so I was wondering which of these plugs this goes through. I have got the copy of the diagram shown and also the genuine ford set but cannot see the three plugs shown on any of them. Thanks again David