D47J takes a long time to fire up. Usually main motor is warm before regular firing gets going. Prob hard on pony having to run it so much. I thought maybe main motor having over 5k hrs on it might be a bit low on compression making starting difficult. After its been running, and stopped, it will start right up tho! A friend thought maybe it was an injector issue. So, 2 questions, how does one check the compression on the main motor? Specs? And, what kind of injector problem would make for hard starting? What would need to be done to fix any injector problem?
Thanks for any help, Bob

PS I won't be able to start cat. til pony rebuild is finished, and that will be after I locate a couple .020 main bearings.

Let it warm up longer on compression so the air gets hotter in the cylinder area. Alot of guys switch from start to run to soon before its warm enough and it will just sit there and spit and cough till theres enough white smoke to see from the space shuttle.

It,s ok after a little bit to put the lever in run but don,t turn the throttle on so it,s trying to start and do as you say let it run for a little while to built up more heat from the compression. Also a slight sniff of starting fluid in the air cleaner will help in cold climates.Low breaking pressure on the spray nozzles could be a problem or the lifter screws that lift the injection pump screws might just need adjusting. The best way to check nozzles is go to a dealer or inj. shop and have them checked for breaking pressure.

Injectors may just be dirty. Get some diesel fuel conditioner/injector cleaner and double up on amount listed on bottle. Run engine till it warms up or all day for that matter. Then see if it starts easier the next day. This will be easier than the above posts just to see if it works. If it doesn't, you will have to follow the advice in the above posts.
My .02 cents
C u............Claney