3406c mechanical question

Some one could of very well played with the screws , who really knows??
Why do you think its low on power?
3zj are very lazy to begin with , static timing on those if im correct is 8 degrees.Compare that to a 7fb at 24 degrees or even a 4mg at 18 its retarded ( no pun intended).
Put it this way. Boost should be 18-21 psi. Thats cat spec for a 425 .

If your getting that your in spec if not could have other issues.

 

What @swaan said. EPA got involved with the later B and C models. Timing sucked, efficiency sucked, power sucked too, depending on its rating.

 

Heck even my 92U 3406's timing isn't so hot. 10 degrees initial timing vs 22.5 to 28 degrees for the other listed arrangements (assuming no one has monkey'd with it in the last 36 years of course).

 

Im not 100% sure whats involved in getting those Cs with the program.

I do know they can be built to pull good. I think it involves a different nozzle.

You might just try doing a search on here.

I do know sledman had one . He knows the ins and outs of making one perform.

Maybe send him a pm.

 

The 7e-5888 pump is right for the 3ZJ. I would set the time between 17 and 18 degrees dynamic, make sure the advance is working. Also check for leaks on the pressure side. Have injectors pop tested and make certain they have the right washer under them. At its age anything could have been done at anytime. Usually they àre lazy starting with plunger problems. I don't like to see fuel pressure below around 30. Honestly you may be better finding a sure nuff mechanical CAT man and getting it looked at. There are alot of variables from AFRC being bad to having been backed out too far. Weak spring in the governor etc