706 w/282 high rpm miss

My 706 has developed a high rpm miss I'm still trying to track down,
Knowns:
Removing air cleaner nearly eliminates it (if not totally)
Air cleaner tube from air filter housing to intake is sucking together (normal?)
Bled all injectors, each creates a miss.
Replaced fuel filters.
The last cylinder injector line has a hard "hit" to it.
Checked injector pump timing with TDC, lines match up (roosa).
Starts fine, idles fine, miss is bad at 1500+ (white smoke).
Unknowns:
Compression test not done yet.

I plan to replace air filter, maybe air tube if air filter doesn't help. Perhaps run some injector cleaner through it before I get too deep (head would be next).
Any ideas are appreciated. I'm new to diesel engines.

You have already got it figured out! If removing the air cleaner element solves the makes the problem go away that is where to start. Since you do not have a turbo charger you will have maximum air flow through the filter at high idle. If the hose does not collapse at high idle it will probable be Ok but if it has been oil soaked and is soft it would be a good time to change it also.

sounds like a bad injector. it should be the one when you loosen the line that least affects engine performance. this way you can track it down to the exact cyl. can be a valve also, compression check is good idea.and also when you loosen the line to the bad cyl the white smoke will dissappear.

You need to determine if the automatic advance is working on pump. You will need a timing window to do this and observe it while running. The mark on cam ring should move (don't quote me on this spec) 1 & 1/2 marks at about 1800 rpm.I would have to check the manual to be sure. This pump has a speed advance where as 282 used on all but first 656 gear drive and all 4 and 560 have a load advance which works differently. If it does not advance it will miss at high rpm. Fuel pressure needs to be correct for advance to work as it it operated by fuel pressure so fuel filters are first thing to be sure are good. There is a trimmer screw to fine tune the advance. May have to put a gauge on to test pressure. The air hose should not pull in, if it does you have restriction in filter or before filter, (bird nest in inlet). Your static timing should be one degree btdc on a 706 and that might help. Don't advance more than that as that will have detremental effects even though it may well clear up your miss and smoke. Very common problem with these engines. Don't try moving pump to advance timing while engine is running as this can cause pump siezure and wind you up like a pretzel.

Update, new air filter cured it. The old one didn't look that bad but apparently it was.