[Jmcann]

Hello. New to this forum. I have done a lot of research so I am aware there are many forum postings about black smoke but none of them seemed to match my circumstances. My truck started bellowing out black smoke and at the same time act like it is starving for fuel when I hit the pedal. Then finally a couple of days ago it stalled and wouldn't start. I had to have it towed back to my place.

Since then I have tried priming the fuel and got it to start again, but usually it just dies again. But I have done that more than once where I prime it and it starts. Then eventually quits.

So I have read a lot of posts online. Most of them indicate the wastegate as the issue But I have read that most of the causes are either fuel injectors, fuel injector pump, EGR, filters or the Turbo. The last three I could see causing the smoke but not my stalling issues. So I am leaning towards fuel pump, fuel injection pump or fuel injectors.

Any thoughts? Also, how do test these components? I dont want to order all of the parts and I don't want to order one to find out it isn't the issue. These parts aren't cheap. Can I test most of these components out using a multimeter? Like I have no idea how to test injectors. There is a check engine light on and I my code reader didn't work so I need to go by a new one and I can't provide the codes in this post. I was thinking about picking up a Fuel Pressure Tester too.

Thank you very much for your time.

 

[Spoolin'It]

Did this happen on a recent fill up of fuel? Or has it been getting progressively worse on more than one fill-up?
Start by getting the codes, that will tell a lot. It could be something as simple as a coolant temp sensor puking and it commanding full rich, or even the mass airflow sensor dying.
Did you try changing the fuel filter?

BTW its a 6.6L diesel, the 6.5L was the previous generation to the Duramax trucks.

 

[OkDually]

Hello. New to this forum. I have done a lot of research so I am aware there are many forum postings about black smoke but none of them seemed to match my circumstances. My truck started bellowing out black smoke and at the same time act like it is starving for fuel when I hit the pedal. Then finally a couple of days ago it stalled and wouldn't start. I had to have it towed back to my place.

Since then I have tried priming the fuel and got it to start again, but usually it just dies again. But I have done that more than once where I prime it and it starts. Then eventually quits.

So I have read a lot of posts online. Most of them indicate the wastegate as the issue But I have read that most of the causes are either fuel injectors, fuel injector pump, EGR, filters or the Turbo. The last three I could see causing the smoke but not my stalling issues. So I am leaning towards fuel pump, fuel injection pump or fuel injectors.

Any thoughts? Also, how do test these components? I dont want to order all of the parts and I don't want to order one to find out it isn't the issue. These parts aren't cheap. Can I test most of these components out using a multimeter? Like I have no idea how to test injectors. There is a check engine light on and I my code reader didn't work so I need to go by a new one and I can't provide the codes in this post. I was thinking about picking up a Fuel Pressure Tester too.

Thank you very much for your time.

Welcome to DieselPlace
Does your LB7 have any mods? If so please list them.

You mentioned when you prime it that it will run and then stall again.
When you prime the Fuel filter head does the primer button stay hard or does it go soft after some time?
The stock LB7 does not have a fuel pump. It relies on the Cp3 to pull fuel from the tank.
If your fuel filter head has a leak it will allow air to enter and fuel to possibly leak, causing a stalling or no start issue.
There are some Orings inside of the Fuel filter housing that wear out over time need to be replaced.
I would start by either rebuilding or replacing the fuel filter head.
Rebuild kits are available locally or online. Make sure you get a kit that includes the bleed screw.

 

[Jmcann]

Did this happen on a recent fill up of fuel? Or has it been getting progressively worse on more than one fill-up?
Start by getting the codes, that will tell a lot. It could be something as simple as a coolant temp sensor puking and it commanding full rich, or even the mass airflow sensor dying.
Did you try changing the fuel filter?

BTW its a 6.6L diesel, the 6.5L was the previous generation to the Duramax trucks.

Thanks for the correction.

So yes, this happened 4 or 5 miles after filling up where I also put in a container of diesel fuel injector cleaner.

 

[Jmcann]

Welcome to DieselPlace
Does your LB7 have any mods? If so please list them.

You mentioned when you prime it that it will run and then stall again.
When you prime the Fuel filter head does the primer button stay hard or does it go soft after some time?
The stock LB7 does not have a fuel pump. It relies on the Cp3 to pull fuel from the tank.
If your fuel filter head has a leak it will allow air to enter and fuel to possibly leak, causing a stalling or no start issue.
There are some Orings inside of the Fuel filter housing that wear out over time need to be replaced.
I would start by either rebuilding or replacing the fuel filter head.
Rebuild kits are available locally or online. Make sure you get a kit that includes the bleed screw.

I wouldn't say it has any real mods. It has a banks upgraded air filter and an added jake brake system. That is all that I am aware of. I didn't put them on.

 

[Spoolin'It]

Thanks for the correction.

So yes, this happened 4 or 5 miles after filling up where I also put in a container of diesel fuel injector cleaner.

OK first things first, sounds like you got a bad tank of fuel. Call the station you filled up at and see if they had any other problems. Try and pump out a sample or drain the filter into a container and see what you have in there.
My friend pulled his newer Vette in to a station one morning last summer, filled up on what he thought was 94 Octane. Got a few miles away and the thing ran like complete garbage, blowing smoke & missing etc.. Turns out the tanker driver screwed up the night before and topped off the wrong storage tank with diesel.

 

[Jmcann]

OK first things first, sounds like you got a bad tank of fuel. Call the station you filled up at and see if they had any other problems. Try and pump out a sample or drain the filter into a container and see what you have in there.
My friend pulled his newer Vette in to a station one morning last summer, filled up on what he thought was 94 Octane. Got a few miles away and the thing ran like complete garbage, blowing smoke & missing etc.. Turns out the tanker driver screwed up the night before and topped off the wrong storage tank with diesel.

Thank you, I will start with that and getting to codes. Do you have a favorite obc2 scanner?

 

[Spoolin'It]

I would go take a ride by the station right away and see if the pump you filled at is out of service. In my buddies case the station attendant magically stopped speaking english when he figured out why he was there, but the pump handle was bagged off so he knew something was up. He wound up having to call the corporation that represents the station, look around the station there is a 1-800 complaint number usually posted somewhere.
Can't help much on simple code readers. I have an Edge attitude display that will give me codes and AutoEnginuity for my laptop for more advanced diagnosis.

 

[Jmcann]

I stopped by the station and didn't see any signs if issues there. I sucked some gas out of the tank and it looks normal (greenish), smells normal and has the flammability I expect from Diesel. Before I move on I should mention that I had the fuel filter changed a few months ago along with the air filter. There was a lot of water and rust inside the fuel filter.

I went back to the primer and realized I primed it but never drained it. I put a cup underneath, primed it and filled the cup. What came up had a very thin green ring around the edge and what looked like yellow oil in the middle. Not very transparent either. I have attached some pictures to this post but I am not sure they do it justice. I primed and drained about 10 more times to where it was much clearer but still not straight diesel. Then I tried to start it which is the video link below.

I believe the black smoke in the video is from me getting some of the drainage on the exhaust manifold.

Finally, my OBC Scanner device showed up today but I won't be able to get to it until a little bit later this week.

 

[Spoolin'It]

The code isn't going to help much right now, you have a serious fuel problem to get fixed first which likely caused the code in the first place. Stop trying to run it on that stuff, you are only going to cause more damage if the pump or injectors are not already junk.
Based on this happening immediately after a fill-up, you apparently filled up at a station with too much water/sediment( or something else) at the bottom of their tank and now its in the bottom of yours. The fact you are getting that much garbage up the fuel lines still isn't good.
They have to have their tanks pumped/cleaned periodically to get this crap out but some wait too long because its expensive for them to get it done. Call the complaint line for whatever brand you filled at and tell them you got a bad tank of fuel from this station. They have insurance to cover damage from this happening.

 

[Kevinstro]

Yeah. I agree with spoolin it. Sounds like you got a bad tank of fuel. If you’re getting that sort of crud up at the filter, who knows what’s in the tank.