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Hi i have an 01 lb7 that smokes at idle and when you get on it it will smoke a bunch then clear up if u let it sit again idle it then will start smoking again after a few mins any suggestions on the problem? i have videos apparently i cant post them on here?
 

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Hi i have an 01 lb7 that smokes at idle and when you get on it it will smoke a bunch then clear up if u let it sit again idle it then will start smoking again after a few mins any suggestions on the problem? i have videos apparently i cant post them on here?

is it white smoke, black smoke or some other smoke? does the color change from idle to "on it"?

given its an LB7, and its smoking at idle, my money is on stuck open injectors. You can look at balance and return rates to see if there shot.

Upload the video to youtube and just post the link if you like.


your second picture looks like its idle haze from bad injectors but the first picture.... thats a lot of smoke. are you loosing coolant at all?
 

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No coolant doesnt move at all its like a blueish and a little white mixed i would say lol and injector brs where tested and they where healthy
 

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Hi i have an 01 lb7 that smokes at idle and when you get on it it will smoke a bunch then clear up if u let it sit again idle it then will start smoking again after a few mins any suggestions on the problem? i have videos apparently i cant post them on here?

is it white smoke, black smoke or some other smoke? does the color change from idle to "on it"?

given its an LB7, and its smoking at idle, my money is on stuck open injectors. You can look at balance and return rates to see if there shot.

Upload the video to youtube and just post the link if you like.


your second picture looks like its idle haze from bad injectors but the first picture.... thats a lot of smoke. are you loosing coolant at all?
Sorry dont know how to tag new on this site
 

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No coolant doesnt move at all its like a blueish and a little white mixed i would say lol and injector brs where tested and they where healthy

white smoke is either coolant getting burned or raw diesel going out the exhaust stroke. im thinking that one of those two things is your issue. blue smoke is oil, black smoke is excess fuel in the combustion stroke (rich condition). you might have a little ring wear contributing to the blue smoke, as its probably burning a little oil, but i dont think that would explain your issue, and if its running good with good power i doubt the rings are shot. How were the injectors tested? were they removed and tested, or is there health based on balance rates?

If balance rates, that is not the full story of the injector health. You need to also compare the return rates with the balance rates to determine if an injector is healthy. I would be very surprised if you had that kind of hazing with perfectly functional injectors.

If the injectors are actually all 100% in spec and you are not making oil, loosing coolant, or otherwise burning a fluid that should not be burned, then im not sure what your issue would be.
 

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No coolant doesnt move at all its like a blueish and a little white mixed i would say lol and injector brs where tested and they where healthy

white smoke is either coolant getting burned or raw diesel going out the exhaust stroke. im thinking that one of those two things is your issue. blue smoke is oil, black smoke is excess fuel in the combustion stroke (rich condition). you might have a little ring wear contributing to the blue smoke, as its probably burning a little oil, but i dont think that would explain your issue, and if its running good with good power i doubt the rings are shot. How were the injectors tested? were they removed and tested, or is there health based on balance rates?

If balance rates, that is not the full story of the injector health. You need to also compare the return rates with the balance rates to determine if an injector is healthy. I would be very surprised if you had that kind of hazing with perfectly functional injectors.

If the injectors are actually all 100% in spec and you are not making oil, loosing coolant, or otherwise burning a fluid that should not be burned, then im not sure what your issue would be.
Yea its still making good power im not sure if its blue or white it looks like a mix of both to me and injectors where hooked to computer and where in spec im thinking maybe a turbo seal? I also heard a fuel rail plug can cause this
 

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Yea its still making good power im not sure if its blue or white it looks like a mix of both to me and injectors where hooked to computer and where in spec im thinking maybe a turbo seal? I also heard a fuel rail plug can cause this
i would not expect a fuel rail plug to cause that. If the injectors were tested in the truck via scanner, that may not be very accurate depending on how they were tested. The truck needs to be up to temp, in park or neutral while not moving and you also need to log the return rates in addition to the balance rates. My guess is still at least one bad injector (stuck open). This can wash oil off the cylinder walls and result in damage to the cylinder and piston if not corrected.
 

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Looks like the classic LB7 injector smoke to me. The balance rates might show alright on a scanner, but if a return rate test is performed on them I would almost bet it would fail. Probably needs injectors would be my guess
 
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+1 on on the above!

My truck smoked like that for a year, the dealer said the injectors were in range, but on the limits. It is actually happening again, got 80K and 6 years out of the last set.
 

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get your pocket book out, injector time
 

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I’m having very similar issues. The strange thing is that it seems intermittent and when I have the issue I pull over and hook to my tester and the balance rates are all in spec. It might be on my tester, ...but how would I check the return rates?
Approximately 70k on new injectors
01 with 280k
 

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I’m having very similar issues. The strange thing is that it seems intermittent and when I have the issue I pull over and hook to my tester and the balance rates are all in spec. It might be on my tester, ...but how would I check the return rates?
Approximately 70k on new injectors
01 with 280k
Checking return rates isn't a test that can be run on a scanner. You have to pull the valve covers to get to the injectors and remove the return pipes that attach to the injectors, and measure the fuel that comes out of the return side of the injectors in a certain time.
 

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I’m having very similar issues. The strange thing is that it seems intermittent and when I have the issue I pull over and hook to my tester and the balance rates are all in spec. It might be on my tester, ...but how would I check the return rates?
Approximately 70k on new injectors
01 with 280k
The balance rates are the adjustment made to each injector to keep the engine running smoothly. If one pair is down on power, the other may go + to compensate, if the cylinder is up on power over the rest, it may go -. The return rate is the amount of fuel not burned, a high return rate may indicate an injector that is blocked, and a low return rate an injector that's stuck open. Normally a plugged injector would go high on the balance rate as the truck tries to get more fuel from it, and a stuck open injector would go low as the truck tries to remove fuel from that cylinder, however they are not always tied together so easily and without both sets of numbers its very hard to accurately diagnose the issue. There is a very good guide on this forum somewhere about the testing process and how to use both sets of numbers to diagnose injectors. Maybe one of the LDS guys knows where that is?

At least that is my understanding, im sure ill get corrected if im wrong.
 
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