Sorry to be back at this subject but tried to start the 91 breakaway today 44 degrees F cummins 190 hp rolled over readily but would not start finally gave it a small shot of ether [ quick start] & away it went but I don't want to use that if I don't have to. Would the preheat air or fuel not be working or does anyone have some suggestions. Thanks

Opinions vary on the cost/benefit of ether. Preheating any engine is the #1 best starting/antiwear procedure.

My father has an old GM diesel in his cabin cruiser. He has used ether for cold starting for years. He argues that used in moderation (1-2 second burst), it saves much wear and tear on the starter, doesn't load up nonfiring cylinders or smoke as much since it starts in about 2 seconds of cranking and all cylinders are hitting in about 15 seconds. Without ether it takes several cranks and then runs lumpy on one or two cylinders, smoking away for much longer. (The people in the marina appreciate the reduced smoke, except when the mosquitos are thick...)

The danger is in over use, i.e. allowing ether liquid to reach the cylinders, washing the oil from the cylinder walls. Worse yet, the accumulated liquid fuel can allow the engine to speed up out of control, causing the cold engine to overrun and be damaged.

I'm not sure how the road pusher diesels like it but I don't think a quick 1 second shot ever hurt anything.

Just have to ask. Did you use the glow plugs

Wayne

No glow plugs on the Cummins 190 HP 5.9L engine.

Some 5.9L had a preheater in the sir intake just below the right angle inlet on the manifold, most do not.
If the engine turned over OK and didn't start, you need turn key on and then depress the throttle about have way down before cranking, crank and let up on the throttle during cranking, do not hold the throttle down after the engine fires and catches. This is the procedure recommended by Cummins. I don't have a preheater on mine and do this when the outside temp is below 30-40 degrees.

BE VERY CAREFUL with the use of ether.

Put in a block heater and turn it on for a couple of hours before you want to fire it up.