861 Diesel rough idle

I just dropped another $600 into my restored 861 diesel to rebuild the injector pump but it still idles like it has a miss. Also, it sounds like it is hammering on one cylinder. The engine has had everything rebuilt including sleeves and pistons. It is the newer one with the balancer. It is even hard to start and I have to snort the air cleaner with starting fluid. I have a 4000 4 cylinder that starts so easy even when it"s cold out (20 degrees) and sounds different when it idles. The 861 has the older pump with the advance bolted on the side. I also have another pump with the integral advance that I tried and it really makes no difference even with rebuilt injectors. I am wandering if some of these engines just idle rough or is there something wrong with it that I have overlooked. It"s annoying to listen to however it sounds and performs good under power with a plow and the black smoke comming out. I"m open to trying anything including degreing the cam if necessary. By the way, I have the timing set at 23 BTD and that"s all the way CC it will go.
The diesel pump service said they would come over and take a look for me but I thought I would share my experiences here first. They really don"t work on too many antique tractors anymore, just pumps and injectors.

cracking any one injector line ( with wrench ) make any more difference than another.

might have one jug acting up.

have you comp tested her?

checked mains and rod shells?

I did check the compression before I did all the work on it but not since, but I will. The crank was polished or turned, can't remember, has new bearings. Also, when I crack a nut on the injector it seems all will cause a miss. That's why I am wondering if a new engine sounds different than one with several thousand hours on it like my 4000.

ok.. all causing a miss means bangin on all 4. any make the knock go away?


i think i'd look at beairngs for scuffing..

I'm not sure if the knock went away or not but I'll recheck this and get back. What do you mean by "a bearing scuffing"?

You might want to pull the injectors and have them checked out. if yu"ve had to rebuild the pump, the injectors ought to be checked. they wear out also.

Are you sure you have the correct idle speed? At low idle speeds you will often hear a knocking sound that caused by the combustion process especially on a cold engine.

what about a valve adjustment? could one be too tight? what about camshaft? was it reworked or replaced? bad lobe could make a "miss".

(quoted from post at 10:30:40 10/09/12) You might want to pull the injectors and have them checked out. if yu"ve had to rebuild the pump, the injectors ought to be checked. they wear out also.

Are you sure you have the correct idle speed? At low idle speeds you will often hear a knocking sound that caused by the combustion process especially on a cold engine.

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From the middle of his original post:

and it really makes no difference even with [b:0ebe481dbe]rebuilt injectors[/b:0ebe481dbe]

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I had the injectors rebuilt before the pump and even had them recheck the breaking pressure and all checked fine so I then did the pump. My next move will be to check the compression and then degree the camshaft to make sure it is opening and closing the valves at the correct time. This knocking sound is why I rebuilt the engine in the first place and actually this is an entirely different engine as my original didn't have the counter balance. My other engine is sitting in the back of the shop with everything intact except the pump. I even thought of swapping all the lines to see if that makes any difference. At this point I am stumped since I have had 5 of these diesels over the years and many others. My newer ones are not noisy at all and even my old 4000 is pretty quiet for the old direct injection engines.

I haven't checked the valve clearance since I set it originally. You know with the old Fords, you have to rip off the hood each time and then the fuel tank. I plan on taking it all off again to check everything out again. As for the cam shaft, I miced all the lobes and picked the best one out of three. All said "diesel" on them and I know some don't so there must be some difference. Some have suggested that the gear is more precise on the diesel ones so the pump can be timed without running out of space. While I have the valve cover off I am going to check the valve timing with a degree wheel on the crank and an indicator on the rocker are to see if it is opening and closing within spec. I would like to do everything at the same time but in an organized style so compressing testing will be last since I have to borrow the tester from the guys at the New Holland dealer. I'll post my findings when I get them but it will be later in the season as fall is a busy time for me.

i didn't say 'a bearing scuffing'

i said:

"i think i'd look at beairngs for scuffing"



scuff

[ skuf ]


1.scrape or rub: to scrape, rub, or wear away the surface of something, or become scraped, rubbed, or worn with use

might be different on a diesel.. but on a gasser you don't have to pull the hood or tins to remove the valve cover...

Injection timing is off, probably a little early.

hey, the valve cover will come off without removing hood or tank on a diesel, ( just use extreme patients)

Denny did you ever figure out your rough idle in the 850 ford Diesel I have the same problem exactly. Any help would be great.
Thanks David