95 F series 873 bobcat running rich

[HUSKER POWER]

Hello, Jeff here. I'm new to the forum and this is my first post. I bought a used 95 F series 873 skid loader with 1480 hrs on it. it always starts perfect, runs good, but it blows alot of black smoke out the exhaust with a strong diesel smell, When I bought this machine it was a trade in on a gehl, they told me that they put a new turbo and injecter lines on, and new hydraulic hoses were needed,I just had the machine serviced, fluids changed and timing belt checked and all checked out fine. My question is why is it running so rich and is there any thing I can do on any ajustments ? The Bobcat dealer told me it would be very expensive to check injecters on the duetze motor, so I didnt have them do it.also the tail pipe is caked with black soot, is this normal ? I was told that when the old turbo went it could have put oil in to the muffler and it is just burning it out, but that does not explane strong diesel smell. Any help would be appreciated. Thanks, Jeff

 

[Tazza]

Its as if the turbo is not doing its job right. It shouldn't run ritch if its getting enough air to burn with the fuel. Turbo engines can run ritch if when its not on boost it doesn't reduce the amount of fuel going to the injectors. I had a friend with a car like this, he didn't setup something on his pump that lowers the fuel when its on idle, it worked just fine, just blew a bit more smoke.
How does it run when the revs are up so the turbo has spooled up?

 

[HUSKER POWER]

Its as if the turbo is not doing its job right. It shouldn't run ritch if its getting enough air to burn with the fuel. Turbo engines can run ritch if when its not on boost it doesn't reduce the amount of fuel going to the injectors. I had a friend with a car like this, he didn't setup something on his pump that lowers the fuel when its on idle, it worked just fine, just blew a bit more smoke.
How does it run when the revs are up so the turbo has spooled up?

I really dont know how the turbo is supposed to sound because this is my first piece of equipment with turbo that i have owned, I know when I wind up my 7.3 in my truck I can really hear the turbo whistle. I dont hear any thing like that. It really seems to have a lot of power but it also seems to use alot of fuel and smokes even at full throttle.

 

[TriHonu]

I really dont know how the turbo is supposed to sound because this is my first piece of equipment with turbo that i have owned, I know when I wind up my 7.3 in my truck I can really hear the turbo whistle. I dont hear any thing like that. It really seems to have a lot of power but it also seems to use alot of fuel and smokes even at full throttle.

You may want to check the air filter. If it is partially plugged you may be restricting the air flow. Pull the filters, start it up and check if it is still smokes as much.
How hard is it to remove one of the pipes to the turbo? You may also want to check that the impeller spins freely.

 

[HUSKER POWER]

You may want to check the air filter. If it is partially plugged you may be restricting the air flow. Pull the filters, start it up and check if it is still smokes as much.
How hard is it to remove one of the pipes to the turbo? You may also want to check that the impeller spins freely.

I just spent $550.00 getting all the filters and oil changed, I about fellover when they gave me the bill. I wont let let that happen again. I'm getting oil flowing free from the turbo oil return line. and the impeller spins freely. and as I said it has about a 1/4 inch of soot built up on the inside of the exhuast pipe.

 

[mrfixitpaul]

I just spent $550.00 getting all the filters and oil changed, I about fellover when they gave me the bill. I wont let let that happen again. I'm getting oil flowing free from the turbo oil return line. and the impeller spins freely. and as I said it has about a 1/4 inch of soot built up on the inside of the exhuast pipe.

It sounds like there may be carbon built up on the injectors. Remove the injectors clean off any built up carbon on the tips. I have done this on several machines and been able to re-use the copper gaskets. The carbon builds up enough to keep the fuel from spraying in a 'good' pattern and increases smoke while reducing power.

 

[HUSKER POWER]

It sounds like there may be carbon built up on the injectors. Remove the injectors clean off any built up carbon on the tips. I have done this on several machines and been able to re-use the copper gaskets. The carbon builds up enough to keep the fuel from spraying in a 'good' pattern and increases smoke while reducing power.

I was going to by a seal kit for the injectors, but I was told they weren't available. I also talked to a shop in ND who builds duetze motors and he said they are adjusted by temperature using a thermal temp gun. I quess there are shims on them from the factory and when replacing the injector they have to be shimmed just wright. Any way to clean carbon using additives ?

 

[TriHonu]

I just spent $550.00 getting all the filters and oil changed, I about fellover when they gave me the bill. I wont let let that happen again. I'm getting oil flowing free from the turbo oil return line. and the impeller spins freely. and as I said it has about a 1/4 inch of soot built up on the inside of the exhuast pipe.

Quote: HUSKER POWER - as I said it has about a 1/4 inch of soot built up on the inside of the exhaust pipe.'

Sounds like you also need to remove the muffler and try to get some of that carbon build up removed. If there is enough to restrict air flow it will contribute to the rich condition.
However, identifying why it is running rich is still your primary concern.
To keep everything clean and running I use a product named Power Service Diesel Fuel Supplement in every tank of fuel. It was recommended to me by both my Bobcat Dealer and friends in the business who swear by it.
Power Service also makes a product named Diesel Kleen® +Cetane Boost®. Both are listed as injector cleaners along with the other benefits.

 

[HUSKER POWER]

Quote:
HUSKER POWER - as I said it has about a 1/4 inch of soot built up on the inside of the exhaust pipe.'


Sounds like you also need to remove the muffler and try to get some of that carbon build up removed. If there is enough to restrict air flow it will contribute to the rich condition.
However, identifying why it is running rich is still your primary concern.
To keep everything clean and running I use a product named Power Service Diesel Fuel Supplement in every tank of fuel. It was recommended to me by both my Bobcat Dealer and friends in the business who swear by it.
Power Service also makes a product named Diesel Kleen® +Cetane Boost®. Both are listed as injector cleaners along with the other benefits.

I was looking thru the manual and I thought these were direct injection, but it looks like there is a pump with the line going up to a injector, can I just buy a new injector ? and if the motor is running can I loosen the nut on the injector line to make the injector stop working to see what injecror is bad ?

 

[HUSKER POWER]

I was looking thru the manual and I thought these were direct injection, but it looks like there is a pump with the line going up to a injector, can I just buy a new injector ? and if the motor is running can I loosen the nut on the injector line to make the injector stop working to see what injecror is bad ?

I was also told when I bought this machine, that they put new injectors, return lines, and new turbo, could they put the wrong size of injectors in it ?

 

[Tazza]

I was also told when I bought this machine, that they put new injectors, return lines, and new turbo, could they put the wrong size of injectors in it ?

I don't think injector size matters as the fuel delivery qty is controlled by thte injector pump. The shims are for the pumps not the injectors too. The ligher the pump sits the later the fuel delivery will be.
Sorry i can't think of more.
Does it use oil? i'm wondering if its burning engine oil causing the smoke.

 

[HUSKER POWER]

I don't think injector size matters as the fuel delivery qty is controlled by thte injector pump. The shims are for the pumps not the injectors too. The ligher the pump sits the later the fuel delivery will be.
Sorry i can't think of more.
Does it use oil? i'm wondering if its burning engine oil causing the smoke.

It does'nt burn any oil that I can see, It also has a strong diesel smell to it. Anyone know what could of happened that would cause the turbo and injectors to replaced at such low hours ? 1400 hrs

 

[Tazza]

It does'nt burn any oil that I can see, It also has a strong diesel smell to it. Anyone know what could of happened that would cause the turbo and injectors to replaced at such low hours ? 1400 hrs

Bad fuel? that can kill the pump and clog injectors.
The turbo could have been damaged by abuse. They need to be allowed to cool after being on boost. So run the machine hard, don't simply shut it down. You need to let it idle for about 5 minutes to cool and have oil moving around the bearings, then shut down. If the previous owner didn't do this, the turbo could have failed from this.
Just a guess though.

 

[HUSKER POWER]

Bad fuel? that can kill the pump and clog injectors.
The turbo could have been damaged by abuse. They need to be allowed to cool after being on boost. So run the machine hard, don't simply shut it down. You need to let it idle for about 5 minutes to cool and have oil moving around the bearings, then shut down. If the previous owner didn't do this, the turbo could have failed from this.
Just a guess though.

Good news, The new injectors were put in 180 backward. I'll let you know how it runs later. Jeff

 

[HUSKER POWER]

Good news, The new injectors were put in 180 backward. I'll let you know how it runs later. Jeff

Well I pulled my injectors yesterday and turned them around 180 degrees and it runs beautifully, absolutely no smoke and I have more power and speed.

 

[Tazza]

Well I pulled my injectors yesterday and turned them around 180 degrees and it runs beautifully, absolutely no smoke and I have more power and speed.

You learn something new every day, i never knew you could put an injector in backwards.
Glad its running like it should.

 

[HUSKER POWER]

You learn something new every day, i never knew you could put an injector in backwards.
Glad its running like it should.

yeah it is a big relief to me, Going thru the trouble shooting manual there are allot of scary, and expensive repair reasons for this but it doesn't say anything about the injectors being in wrong. Luckily I found a young man in Kansas that knows these duetz motors very well and within 5 minutes of explaining what it was doing, he told me that if the injectors are in 180 off, the nozzle sprays against the cylinder wall instead of over the piston.

 

[mrfixitpaul]

You learn something new every day, i never knew you could put an injector in backwards.
Glad its running like it should.

Was there any carbon caked up on the tips??

 

[HUSKER POWER]

Was there any carbon caked up on the tips??

Yes, What causes that and how and what do you do to prevent it from happening again?