LLY: No Power Black Smoke at Random

[ShredLordXx]

Hey Guys I'm hoping you could maybe shine some advice onto this issue... Every morning when driving to work, about 20 minute drive, when I finally get off the highway into town and hit the first red light and stop, when I go to take off again, it shudders and the engine has a weird knock to it, I can push the pedal to the floor and get no power, just tons of black smoke coming from the tail pipe, and then all of a sudden after about 10 seconds it lets go and I have full power again, and is usually good for the rest of the day. I have changed the fuel filter and air filter. No CEL appears, the truck is a stock LLY. I'm at a loss.

 

[AZlml]

Only happens in the morning? Are morning ambient temps much colder than afternoon temps?

 

[ShredLordXx]

Not always in the morning, but they are cooler, I've had it happen to me around 5pm as well, and still at about 15 to 20 minutes of driving, I had went to lowes and loaded a skid of dricore in, and again at a red light taking off, massive black smoke, no power, no acceleration, I just hold the pedal down, and all sudden it feels like whatever is holding the engine back lets go and it just cruises.

 

[ShredLordXx]

It did it again this morning at the same spot it always does, it also occurred last night 3 times. I'm starting to think maybe its my EGR?

 

[WVRigrat05]

It did it again this morning at the same spot it always does, it also occurred last night 3 times. I'm starting to think maybe its my EGR?

Sounds like the egr is sticking open.

 

[ShredLordXx]

It's possible that it could be the EGR, it always reminds me of a few videos I've seen when some duramax's get air in the fuel lines, but I would think If I had air in my lines, that I would have trouble from the get go, and not so much after 20 minutes of driving... I could be wrong.

 

[ShredLordXx]

It chugs hard like a dog barking, while blowing thick black smoke, and then all of a sudden about 10 seconds it clears up and i can take off like nothing, while its chugging like a dog * literally sounds like a retarded dog barking * I can't go more than 30km/h

 

[PureHybrid]

Do you have a scan tool to watch any ECM parameters? Otherwise we are shooting in the dark here. But you can always slap a $10 egr blocker plate in and drive it (off-road obviously )

 

[TheBac]

EGR problem, stuck vanes, or bad vane position sensor. You're going to have to scan the truck and do some logging in order to figure it out. Otherwise, we're all just shooting in the dark.

 

[ShredLordXx]

I hear ya, I don't have any fancy scan tools, I have a cheap plugin one, and ODB FUSION on my phone, it shows freeze frame and certain things, it shows egr voltage and duty cycle, but that's not going to give us anything. Any Scanner Recommended, wont be too brutal on the wallet?

 

[ShredLordXx]

I think, I'm gonna give an EGR blocker a try, I drove it around last night, as I got a call out to go to work, and I drove her really hard getting temps higher than usual, this morning it did not bog down on me, but that could just be luck lol

 

[Wturnbo]

Best egr blocker plate

What are yalls opinion on egr blocker plate scanned my 06 gmc lbz 420453 miles an egr is flowingto much so figured id get a blocker plate for it what do yall recommend as being the best an what to stay away from

 

[ShredLordXx]

I have read that there are a few people that just use the blocker plate on the up pipe, and have had good results, I just unplugged my EGR last night to see if it would help, so far i didn't die on the road today, weird thing is it didn't set any codes or CEL.. pretty strange. Im debating on buying the blocker plate, and two plates on the egr side, with the coolant bypass or just removing the entire egr and replacing it with a high flow air horn pipe.

 

[ShredLordXx]

The only downfall with entire removal, is if I'm ever pulled over for road inspection by the ministry of transportation, I will be in some trouble lol

 

[Dozerboy]

Where do you live? Heck I doubt they even would know if it was gone.


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[ShredLordXx]

I live in Ontario Canada, I doubt that I would ever get caught, they usually don't pull over regular trucks, just big rigs, and because I live in Northern Ontario they don't do emission testing here yet, but a couple hours south they do.

 

[ShredLordXx]

I think the whole thing would come out easy, the hardest part I foresee is taking the bolts out of the up pipe, with my truck being pretty old, * it has survived 13 years of brutal northern Canadian winters* it has some lovely natures lock tight on it. Wonder if there is some kind of trick.

 

[Wturnbo]

Thanks for the info i dont wont to remove it all the way for the fact if i move somewhere that has emission tests. But blocker plate seemed the easiest an the most cost effective.and before i attempt to remove anything ill soak the bolts in pb blaster

 

[2008lmmchopper]

May be a dumb idea but I'd just have the dealership run a check on it or maybe a diesel shop it would still be a cheaper bill then buying a scanner. Then you know exactly where you stand they do all the foot work for you.

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[ShredLordXx]

I unplugged the EGR and it has stopped bogging down at red lights, my idle is slightly off, but It's for sure the EGR in that is causing the Low power and Black smoke from a stop!