Ford 4610 engine slight miss?

[Jerry/MT]

Guys so I'm back working on this tractor but have still not found a resolution yet. First off it's actually a 4600 not a 4610 but still same 201 Diesel engine. We have now adjusted valves which were found to be in spec. We have done a compression test on all 3 cylinders. All are were well in spec per Ford specifications. Injectors were replaced. Fuel filter replaced. Timing was found to be advanced to 7 or so. Apparently someone has been monkeying with it in the past as Ford spec says to start at 0. Seems have more power and smoke less now but the vibration still exist between 1600-1800. Also we put in new fuel shut off valve in fuel tank. So now I'm out of ideas. Anyone have any thoughts as to what could be causing the issue? Also it's engine related as it does it in gear or out of gear. Causes stuff to shake and vibrate badly on the tractor and is very annoying. Thank you[/

Does this engine have a dynamic balancing system? I'm not sure whether the three cylinder engines have them. If it does, your problem may be there.

 

[sawtooth]

No not on these engines but good idea. Thanks

 

[TractorTech]

Doesn't sound like a fuel problem, but rather a bent con-rod as suggested or a headland piston possibly coming apart although it should be running rough or an unusual knocking eminating.

 

[sawtooth]

No believe it or not it sounds great and cranks up fast. No other issues other than vibration at 1600-1800. The funny thing is that back in 2007 I bought a Ford 4000 SU that did the exact same thing. I ran fuel conditioner and cleaner in it for about 4 years maybe but only put about 10 hours a year on the tractor. Then one day after 4 years or so the problem just went away and never returned. Again the 1600-1800 vibration issue. If I didn't know better it seemed like same engine. Lol. I'm going to do the same with this one so maybe issue will go away someday. Just wish I could make it happen faster this time. Both tractors set around for some years before I purchased them.