Smokin diesel at 2000 rpm's

[JimR]

Smokin diesel at 2000 rpm\'s

Help, I need some diesel help please. My 7275 Cub Cadet started smoking today for no apparent reason. I was mowing my field at 2250rpms with the mid mower deck hooked up. The tractor started losing power and started smoking black. If I bring the throttle down under 2000 rpm's it clears up and stops smoking except when going up the hill with the deck running. At WOT without the PTO it stills smokes black. My thoughts are a bad injector or pump. Has anyone else experienced this with their diesel tractor?
TIA, Jim

 

[Phil_R]

Re: Smokin diesel at 2000 rpm\'s

Recently had a similar problem with my son's Yanmar... any load on engine produced black smoke and not much power. (black smoke indicating mixture too rich) Cleaned/replaced air filter, still smokin'... Removed muffler and replaced with straight pipe, no more smoke. (and the power was back to normal level) Cut open muffler and found it clogged with soot.

 

[JimR]

Re: Smokin diesel at 2000 rpm\'s

Thanks for the info, I will have to check out both of those as possibilities. The muffler looks to be an original. I know I cleaned the air filter when I mowed for the last time last fall. Maybe a mouse moved in and plugged it up. I did put in a can of injector cleaner and ran it for 20 minutes tonight. It started smoking as soon as I cranked it up to 2000 rpm's.

 

[Soundguy]

Re: Smokin diesel at 2000 rpm\'s

I'd check air filter first, then fuel filter.

When one of our diesel trucks/heavy equipment starts smoking black, 80% o fthe time it is a clogged air filter making a rich burn.. the other times are the fuel filter.. and that deffinately saps power.. etc. Ya might have both..

Soundguy

 

[JimR]

Re: Smokin diesel at 2000 rpm\'s

Well it's not the air filter, fuel filter or the injectors. I pulled the air filter completely out, changed the fuel filter and it still smokes at WOT under a load. So I pulled the injectors and tore them down for a good cleaning. Those things are pretty simple. Just rememebr not to get anything in them. I then went out to do some mowing. The tractor was running fine at WOT until I hit a heavy section of grass. The motor slowed down a little bit and started blowing black smoke again. Now this is the puzzling part. The tractor will run at WOT without smoking until I nail it with a heavy load or try to climb a hill in too high a gear to make it bog down. Then she starts smoking at WOT wether I am pushing the tractor to work or sitting still. This is leading me to believe that the governor is sticking in wide open. What a pain in the arse this is to figure out. I hate to have to pull the front of the motor apart to check out the governor. Oh well, it beats taking it to the dealer. I may pull the injector pump off to see if something is sticking in there.

 

[DmaxEter]

Re: Smokin diesel at 2000 rpm\'s

Its a Diesel engine. Black smoke means unburnt fuel. You are not getting enough air to burn the fuel or you are getting too much fuel to burn. It needs to be delivered at the right time also so timing may be an issue. Make sure the injection pump is still mounted tight to the engine and hasnt turned a little. Thats all the info I can help with. I will take a wild guess and say its not a turbocharged engine.

 

[JimR]

Re: Smokin diesel at 2000 rpm\'s

Today I was using my tractor and it was running fine for a short period of time as usual. Then the smoking started. I found the problem this time. Somehow the air filter is plugging itself up. Maybe it is old age or whatever. I can blow compressed air thru the filter from the inside out. But the filter is closing itself off somehow when running. Here is what I did that gave it away today. With the tractor running at 1200 rpm's I tried to remove the air filter from the canister. I could not get the filter out without prying it with a screwdriver. Once the filter was out the motor revved up a few hundred rpm's. So I took the tracotr out with the filter missing and proceeded to put the tractor thru its paces in a mowed filed to keep the dust out of the picture. The tracotr ran fine at WOT and no more smoking. Tomorrow I get a new air filter for it. It just never ends.

 

[JimR]

Re: Smokin diesel at 2000 rpm\'s

Ouch it hurt the pocket book this morning. New Mitsubishi air filter for my Cub $81.00. Ouch that hurt.

 

[normde2001]

Re: Smokin diesel at 2000 rpm\'s

"Well it's not the air filter, fuel filter or the injectors. I pulled the air filter completely out, changed the fuel filter and it still smokes at WOT under a load."

Now that's confusing, to say the least /forums/images/graemlins/confused.gif.

 

[GaryK]

Re: Smokin diesel at 2000 rpm\'s

But just think of the peace of mind you have now........ /forums/images/graemlins/smirk.gif