So today I tried the cruise on my 740, having replaced a couple of vac lines and the throttle spindle on the weekend. It now works fine - so I'm very happy
Thanks ngoma for the help, much appreciated. I'm still not sure whether it was just my not connecting the pump correctly that meant that it didn't work on test...
Very happy with it, it made the 120 miles this morning go even quicker than usual!
Jim