2001 LB7 Continued Diagnosis of Idle Smoke

[duratothemax]

Originally Posted by daschae

I 2nd the two stroke oil suggestion. The white smoke wouldnt indicate a bad FPR, the rolling idle could. Does it sound loud at idle...and what I mean is the injector "knack knack knack knack knack.." Is it louder than other LB7s you have heard? If your FRP sensor is bad, it could be adding too much pressure at idle which makes the injectors loud and starts to F up a smooth idle. My 03 is quiet at 35kpa idle rail pressure, my 01 is loud and has a rough idle, if I turn my rail pressure down, it quiets up and smooths out.

And someone else chime in here, a cracked injector wouldnt neccesarily show a bad balance rate. White smoke says your getting too much fuel at idle... so either leaky injector (cracked, bad seat, whatever) or FPR sensor.

My guesses.

Start with the bottle of 2 stroke.

It was not louder than any other LB7 at idle IMO, but it did have a surge, and like I said, desired would not follow actual rail pressure at idle.

Cracked injector or leaking ball/seat would show a bad balance rate because it would be injecting too much fuel into a certain cylinder...which would cause a bad balance rate as the ECM tries to compensate for a cylinder that is overpowering the others.

If you look up in eSI (gm factory service manual that the dealers use), the diagnostic flow charts all point to a bad regulator, and say to replace it...I realize those arent always right, but every other LB7 ive had with these symptoms had a bad regulator.

[bigdaddydiesel]

Just so it is covered.

2003 LB7. Two sets of injectors replaced before 42K. 102K miles now with no rough idle, no smoke, no white haze. Nothing but a smoother running, quieter Dmax that pulls like crazy. I use a combo of Diesel Concentrate AND Cetane Booster from Amsoil in every tank. IMHO it is worth testing, most that have tested this combination have had great results. I have heard zero negative feedback from those that have used the combo according to the instructions.

Anyone who would like to test it for themselves, let me know and I will get a couple of bottles of each sent so that you can decide for yourself whether they work as well as we claim....

Have a GREAT day and good luck with your issues.

[phatfox77]

Duratothemax,
I agree with you with everything that has been happening. I really wish the FPR had fixed the problem. I guess we just need to figure out whats cause that surge at idle and dumping the extra fuel....

[duratothemax]

Originally Posted by phatfox77

Duratothemax,
I agree with you with everything that has been happening. I really wish the FPR had fixed the problem. I guess we just need to figure out whats cause that surge at idle and dumping the extra fuel....

Sent you an email with the schematics. The ECM is kinda a PITA to remove on the LB7's, let me know if you get stuck on anything.

Ben

[DuraTitus]

I still think it is your injectors......

Injectors are the only thing that could cause the white smoke, unless you have a coolant leak.

[duratothemax]

Originally Posted by DuraTitus

I still think it is your injectors......

Injectors are the only thing that could cause the white smoke, unless you have a coolant leak.

the white smoke was unburned fuel; thats what the smell was.

[phatfox77]

I did the injectors this weekend. took me saturday and sunday. job went well, Duratitus injector replacement post was very helpful. Once again the idling white smoke problem has been solved by changing injectors. I changed all 8. Not too bad of a job, truck is running amazing!!!...

[DuraTitus]

Glad you got the problem fixed, and good to hear my injectors worked good for you!

Congrats!

[redneck1]

im having very similar problems with my 02 lb7 ive had it for three months now,it has 147xxx and i noticed the injectors have been replaced once already,but the smoking problem with it stumps me,when its nice out and sunny it wont smoke at all but when its damp and rainy or snowy out itll smoke,no loss in power,no loss in mileage,doesnt idle rough and no injector knock...and its only been doing it for about a month since i have owned it, i drive it a half mile down the road and the light smoke clears right out
thanks

[redneck1]

so im having a similar problem... i have an 02 lb7 with 147,xxx and the injectors have been replaced .the smoke has got me stumped. it only really smokes when its snowing or raining (damp out) and when it does smoke it only smoke at idle and at drive for about a half mile down the road and itll clear out. i changed the fuel filter because that was real dirty. i have no loss in power what so ever no loss in mpg,its no louder than it was before it started smoking,no injector knock or abnormal sounds so i dont know.....