1993 topkick with 3116 cat is hard to start every morning, replaced intake heater,check valves,filters, shut off solonoid, installed electrical fuel pump( mech still operational) engine does not lose fuel back to tank, most mornings have to spray with quick start. Heavy smoke when she first starts then she runs fine all day. I'm thinking fule may be leaking past injectors overnight, is that likely or any suggestions on what could be most likely cause ?
Check the fuel filters if they are properly bleeded and full of diesel. Check your diesel feed pipe if it has a good flow of fuel when you losen it.
It is a sign of injectors needs replacing or adjustments
Yes the combustion is leaking by the injectors causing air in the fuel system that is noticed only on start up. Plum in a clear plastic tube on the return and you will probably see excessive air in it. If you pull injectors you should be able to see which one(s) are leaking by. Then there is a kit to cut the brass injector sleeves so they form a good seal with the injector as it is just a brass to metal injector seal. Then another kit to seat the injectors properly, then another kit to set the timing and synchronization of the injectors. By the way I cut a sleeve today and am setting up the racks on a 3116 in a truck for hard starting............
99% of the time if you have a problem with injector sleeves then you will see diesel in the radiator
There is not a problem with the sleeve itself. The problem is with the injector to sleeve seal. There is no o-ring or copper washer to form the seal just sleeve-to-injector. That is why there is a tooling kit to cut the sleeve up to 4 times to re seal (re-seat) the injector-to-sleeve when the seal has failed or wont hold back combustion gases. Diesel in the coolant is a sleeve-to-head seal problem not injector-to-sleeve seal problem.