Cold starting a 51 Cat

[LT40HDD51]

Just did a good cold weather tuneup on our mill, thought I'd let you guys in on it. It was starting real hard whenever the weather was much below freezing (weve had a mild winter up until recently).

After a closer look, found we had a problem with the glow plugs not working. Seems when one fails it can short out when it goes. Then next time we used them it burt out the 50 amp fuse in the little black box on the side of the engine. No glow. WM tells us that the glow plugs shouldn't stay on longer than 17 seconds in one shot. More recent Cat mills are equipped with a resistor that kicks them off in time, early Cats didn't. They tell us you can give it repeated 17 secong shots to the glow plugs in really cold weather before starting, but one big one will kill plugs. You can get this resistor from WM to add to your mill, I'll get the part number when I get back to the shop if anyones interested...

Second problem was that the idle wasn't quite high enough. When the engine did start it would rev up and die. After turning the idle up (just a bit) the engine started great. We also put a block heater in the middle frost plug on the side of the engine, we're ready for the cold now  ;D.

Hope this is of some use for someone out there