I have a 751C with the Peugeot engine. The indicator light stays on for about 5 seconds. The manual indicates the power to the glowplugs goes off when the light goes off, but I've verified this is not the case. The glow plug relay actually drops after about 12 seconds. I really don't know what the time is supposed to be. Mine sure puffs blue smoke on a cool (15 deg C) morning when if first starts. Going through several rapid glowplug cycles does not seem to make any difference. Then other mornings it starts with very little blue smoke. Not sure what's going on. Perhaps I have an intermittent plug? Seems this would only cause it to miss. I am dissatisfied with how it starts when cold since the dealer put in a new injector pump. Did not seem to have this blue smoke before. ---Bob
Problem SOLVED.
One of my dad's friends came over and when i was starting the 743, he said it looks like it is over fueling, he asked if i was sure the glow plugs were working. They got warm, and drew power so i figured they were ok.... WRONG, i took one out and you could instantly see that they were stuffed, they were not parallel, they looked like an hour glass. I hooked one up to the battery and it did glow, but only a small section at the base of where it screws into the head, not where it the fuel squirts on to. So i swiped a set from another machine that were good, hooked them up and 20-30 second glow and it starts rite up. Unlike before, i had to glow for about a minute then crank and crank and crank some more and it may start, then stop. Glow a bit more then crank and then it was ok (maybee).
So, if you ever have starting troubles, pull out the glow plugs and be sure they are ok by hooking them up to a battery and they should glow rite to the tip within 10-15 seconds. I just wish i picked up on this earlier!!!!