Smoking Cummins 855

Never saw much benefit altering from the book unless it was something like advancing the timing when increasing rated speed. So I would go with the book. Does the lift really increase .01 at the end of the OBC and not .001? I do not know anything about that one way or the other just curious.
However I watched some guys through buckets of money at one doing exactly what you are talking about. Finally it went to Cummins and they fixed it. Said the overhead was not ran properly.

 

My suggestion is to run the over head again but when you get close to the letter on accessory drive you need to look at the injector push tube or rocker and make sure it comes all the way up, this is the only way to take variables out and ensure you are at the peak injector lift.

 

What state are you in?

 

You may have went to Cummins at the time, I am hearing more and more that people have been turned away from Cummins dealers because they have no one familiar with those engines.

 

Same with cat. Ever try take a B model in to get the pump meter timed?
You just get the deer in the headlight stare. The old timers are gone.

 

If the engine seems to run fine on the road & smokes, runs rough at idle i'd focus on the stc system. The stc valve supplies oil to the overhead at idle, light load conditions. An oil leak in the overhead can cause the engine run as you describe as some or all of the injectors stay in normal time. The plastic oil jumpers beneath injectors are prone to failure, there's a plug that blows out causing a huge leak. I'd run it with the covers off & see if anything shows up.
Outer base method is the way to set the overhead & Box Car is correct that the stc pressure should be removed prior to adjusting. Cap off the signal line to the stc valve at the shut down solenoid, connect regulated air to the stc valve control port & switch the valve into normal time while the engine idles. While in normal time at idle the engine will smoke, run rough & be very quiet. The injector adjustment varies depending on the cpl should be 90 inlb but I can double check on Monday.

 

I thank the first two pages are out of order.