Hey folks I feel so stupid, Here I thought I had 4 bad glow plugs, Well maybe the first. It turns out that my glow plug igniter had a broken wire and it intermitantly made contact and when it did not I assumed the plug burned out so changed it... Alan

Not stupid Alan - these things can be confusing. At least you now have some spare plugs AND you know your plug problem has been "cured." I think this is good news all-round

Tony