Puffing black smoke

[GMtb42]

I noticed since I got the tractor that it intermittently puffs black smoke at idle or full throttle.
Just a short puff but seems to happen quite regularly almost as if a injector is squirting more fuel every once in a while.
I changed the fuel filter thinking maybe it was the problem but it still does it, no worse or better, any ideas as to what may be causing it, bad injector, debris in injector, etc....

 

[EssexBoy]

It would be the injector pump and not a injector, and not something that you could do.

 

[VictorW]

If it seems like it's one cylinder giving that "one puff" of smoke intermittently, I would think it's an injector and not the pump. Others, who may have had a similar problem, hopefully will post their repair. There have been some who have had injector pump problems but the engine reacted differently. Is it under warranty? I would start with the injectors but the hard part is which one being that it is intermittent.

 

[DT86]

I would start with the injectors but the hard part is which one being that it is intermittent.

I agree start with the injectors. Pull them all and have them tested. It's pretty cheap.

 

[JD5210]

Close to your question. When going from an idle to increased RPM my tractor (99 JD 5210), would give off a puff of smoke. I started using JD fuel conditioner and after a few tank fulls the puff of smoke went away and the tractor now starts with just a flick of the engine.

Something to consider before pulling injectors.

 

[ritcheyvs]

Maybe injectors, definitely not the IP. Possibly clogged air filter. Black smoke is unburned fuel. A little smoke (often white) on startup is no big deal. Black smoke at high power settings is either poor fuel atomization (injectors) or choked air supply (clogged air filter). Note this is at high power, not just high RPM. In normal operation the governor constantly increases and decreases the amount of injected fuel to maintain a fixed RPM. Smoke puffs occur when the governor demands more fuel.

I'd try an injector cleaner before any disassembly. Diesel Purge is a favorite with old Mercedes Diesel owners:
http://www.dieselgiant.com/injectorcleaning.htm

 

[Soundguy]

if it was on my machine.. I'd change the filter and fill it with a injector cleaner like power service, then do a standard 'double dose' on the tank, and then service the air filter.

if the IP has a oil lubed cam box.. I'd service it and make sure it was not fuel thinned.

I'd also check the engine oil to make sure it was not fuel thinned.

thinned oil in the IP can cause issues.

thinned oil in the crankcase can lead to oil consimption and reduced lube.

post back

 

[GMtb42]

Thanks Vic, my thoughts as well. No,no warranty.

 

[GMtb42]

if it was on my machine.. I'd change the filter and fill it with a injector cleaner like power service, then do a standard 'double dose' on the tank, and then service the air filter.

if the IP has a oil lubed cam box.. I'd service it and make sure it was not fuel thinned.

I'd also check the engine oil to make sure it was not fuel thinned.

thinned oil in the IP can cause issues.

thinned oil in the crankcase can lead to oil consimption and reduced lube.

post back

Will try that and see. The oil/air/fuel/hydraulic filters I just changed and didn't notice any thinning in the engine oil.
Bought used so don't know history behind a lot of things, fuel filter was very dirty, not clogged but had particles of look like rust or scale from something, fuel container/dispenser maybe.

 

[VictorW]

I too would try a diesel injector cleaner first and usually it doesn't hurt anything if you add a little more. You mentioned that there was some rust or scale in the fuel filter bowl. Hopefully the filter caught all of it but if some made it through, that could make an injector hang up now and then no matter what the engine speed is. Probably the worst part is injector cleaner may not disolve that type of contaminent. If small enough, it may break up and get pushed through. It looks like a new injector is @$90. If the problem continues, it might be better to have them cleaned and set. Although I guess you could just buy one and keep changing positions until the problem stops.