Well, with what I learnt from you guys and some encouragement to unclog and clean the injectors from Gregory, I managed to get all three dysfunctional injectors working.   Subsequently I was able to start the engine and get it to run.    The oil pressure light goes out,  The alternator light goes out.  
It seems to run on all 4 cylinders but there are lots of noises of things that should not be there. Probably from things that I did not install properly 6 months ago so now the real work starts.      Thanks for your good tips.  I feel sure I will be back for more.     Steve