White smoke and misfiring at idle

[yzguyisback]

I have a 2001 6.6. When I start the truck, it idles fine for a few seconds, then starts misfiring and blowing out excessive amouts of white smoke. If i rev the truck up, it blows black smoke and will stop misfiring for a few seconds. I cant feel any noticable power loss, the truck runs fine when it is moving and still blows black smoke when i get on the throttle. I had the dealership change the injectors, and all filters, but its still doing it. They told me it was because of the mass airflow sensor. I replaced the MAF and reset the computer, but its still doing it. Ive tried taking the banks system off of the truck, but that didnt help either. The only other thing i can thing of is the fuel pressure regulator. Any ideas? thanks guys

[Mark Rinker]

Hmmm...not a typical set of circumstances. Were any codes set - or is the Service Engine Soon light illuminated? White smoke at idle with new injectors doesn't add up. A new fuel pressure regulator would be minor compared to the new injectors already installed.

Injector Pump? Maybe one of our dealership techs can give you some ideas how to troubleshoot a bad pump?

More information on mileage, modifications, etc. in your signature block will help.

[yzguyisback]

Yeah.. sorry. Theres only 65k on my truck. I have 4 inch exhaust, k&n intake, banks power chip, banks big head. All 8 fuel injectors were replaced less than a month ago. All filters were changed, fuel tank was drained, mass airflow was replaced. I made an appointment to take my truck in on monday. The service tech at my dealership said they might have put a bad injector in..? The check engine comes on and off as it pleases, and when I run the code it says Cylinder 4 misfire detected.

[DmaxMaverick]

Welcome to the Forums!

It could be as simple as an injector that got contaminated during the install. It happens, and the R/R procedure has specific cautions to help prevent it.

[yzguyisback]

motor blew up. started knocking real hard, shaking, then stopped running. new motor on the 17th. under warranty

[Duramaster]

How did you manage to get the engine covered under warranty? Was the truck put into service late? :confused:

[NutNbutGMC]

motor blew up. started knocking real hard, shaking, then stopped running. new motor on the 17th. under warrantyAbsolutely great. New motor.

I swear, with this being my opinion only, after owning two LB7s, GM crapped in their own washtub with that engine. To those that have had good luck, I commend you and envy your luck or your wrenching skills.

I am seriously considering bailing GM all together, even with a 2007 LBZ with less than 2000 miles on it.

GM ==> Shame on you. ..I.

[Mark Rinker]

Wow. I couldn't disagree more with that.

After owing 5 Duramaxes and towing the snot out of all of them - I'd choose a FLEET of 2002-2004 LB7s over the newer engines.

Why?

First and foremost - better towing mileage. Period.
No EGR, catalytic converter, or DPF systems to maintain over time
200K injector warranty - easy to get approval
Cool runners - no overheating problems
Easily and inexpensively turned up - cheap tuners and wastegated turbo mod is simple
Lots of LB7 takeout engines available now for cheap to repower if you do wear one outSounds to me like the truck that blew an engine had injector problems and got driven into the dirt. Once they get bad, you must shut them down or risk BIG problems. But, they give ample warning, far in advance of that.

[yzguyisback]

How did you manage to get the engine covered under warranty? Was the truck put into service late? :confused:

They told me to take all of the banks stuff off of the truck and they would replace it for free under warranty. It produced in late 01 and bought in 02. The diesel service technician sold me a new wastegate he had taken off someone elses truck and I dont think its the right one. I took the banks one off and the brackets are different. Has to be stock before 7 am tommorrow.

[Mark Rinker]

...good luck with that. :cool: