last week i posted a smoking at idle thread i thought i figured it out as i run 40% used motor oil and thought i had put some nasty oil in the tank but now after two tanks of green bought at the pump diesel it still does the same so being the diagnostic wiz i am :rofl: i took my propane weed buring torch and placed it at the tail pipe and the smoke is being burned by the flame and i could see slight black smoke like raw fuel out the pipe burning and it is so now i know its a leaking injector YAY WHAT FUN :violin: need ideas on what to put back stock or 20% or 50% i dont know i dont plan on doing rods anytime soon but i do have a spare stock turbo give me some ideas good and bad thanks
LLY: smoking at idle figured it all out
- Thread starter 05maxlly
- Start date
My truck does this at idle as well. It doesn't do it all time and it's not consistent either. I tried to get the tech's at the dealership to test balance rates but they say they can't because GM will not allow you to just go in and check them. There has to be a reason to warrant the check. I said "It smokes at idle". I guess that's not good enough
well that guy is lying to u i had a few -3s and mine smokes everytime i start it and all the time at idle any shop with a good scanner can pull ur balance rates
What do your balance rates look like? Why are you so sure the injectors are bad? LLY's are not known for the injectors having problems.
raw fuel out the pipe all of a sudden balance rates -3.4 -1.8 seem like a leaker to me but enlighten me
How many miles on the truck? does the truck make full boost? Black smoke on a stock tune would point to a lack of air. Do you have a modded regulator in the cp3?
Have you had the return rates checked. I know on the LB7 the injectors are not considered suspect until the balance rates are +/- 4
You might have a sticking regulator allowing too much fuel or a MAF sensor going bad doing the same thing.
Just some things to look into before you spend a grand on injectors
Just some things to look into before you spend a grand on injectors
double checked the fpr on tech 2 along with mass air flow all look good the fpr is flat lined no spikes like it should balance rate in cylinder 8 still way off from the others so it was suggested to pull #8 injector so i did and it looked dirty but i have never seen one before so dont know pulled the nozzel off and blew air through it and put some pb blaster in it and blew it out with air so i could see the spray pattern it looked good and all were flowing strong put it back together after cleaning injector tube in the head looked good for not having the brush kit and the balance rate is worse more negative still lots of smoke and sounds like fuel knock in #8 cylinder so i cut it off and pulled the injector back out so i can turn in for a CORE in the morning
double checked the fpr on tech 2 along with mass air flow all look good the fpr is flat lined no spikes like it should balance rate in cylinder 8 still way off from the others so it was suggested to pull #8 injector so i did and it looked dirty but i have never seen one before so dont know pulled the nozzel off and blew air through it and put some pb blaster in it and blew it out with air so i could see the spray pattern it looked good and all were flowing strong put it back together after cleaning injector tube in the head looked good for not having the brush kit and the balance rate is worse more negative still lots of smoke and sounds like fuel knock in #8 cylinder so i cut it off and pulled the injector back out so i can turn in for a CORE in the morning
Well I think you found the culprit then. Just FYI you need to electrically charger the injector to open the nozzle to check the spray pattern.
Let us know how it works out for you. I will be doing the same thing on a my buddies LB7 this weekend
now that i have slept on it does it make sence that all the injectors are clogged and being this one is now clean and flowing that the rest of them are just more clogged i think it makes good sence
got it fixed all the injectors had a poor pattern some had to be dripping causing all the smoke and raw fuel out the pipe wasent that tough to pull all of them and clean um glad i did it now
I think that is what I need to do
Did you clean them yourself? What was involved? and how long did it take you?
I think that is what I need to do
x2?? any special tools needed? is all your smoke gone?
Last edited: