2005 lly smoking and coughing

[Claven]

A friend has a 2005 lly in his shop for smoking both black and white, the truck jerks and pings while it happens. We can get it to happen if we accelerate nice and slow from 50 mph and up, right in that lugging range. He has a diagnostic scanner and when we disable number 7 injector while its happening, it runs fine. He changed that injector, but it is still happening. Any suggestions?

[Dakster]

I'll preface this by saying I'm not a mechanic by trade. I'm mechanically inclined and I read, read, read, before I do. I'm sure the techs here will jump in... However, I would check eletrical connections to make sure they are making a good contact. Also, there was a post about certain year trucks getting rust in the fuel lines and causing all kinds of havoc. The procedure was remove all injectors, clean, and reinstall - including the fuel lines themselves.

The previous person just replaced the indicated injectors and still had the same problem until removing, cleaning, and replacing. Obviously, check o-rings or in the case when I've had to change injectors I just replace with new o-rings to be sure. I believe (don't trust me totally) that brake-clean was used.

There may be a TSB regarding this with instructions on how to correct, that is where the techs here can REALLY help you out.

[Duramaster]

Claven:

A couple things to check.............. Did you remove the fuel filter and dump it out to check for water? Is the fuel clean and clear? There are a couple of things electricly to check for. 1) check the harness routing at the FICM. It sometimes chafes through where it is attached to the FICM bracket. 2) There is a bulletin regarding the #2 and #7 injectors connectors where they are broken just right to cause an intermittent connection inside the connector itself. Here is the P/N for the kit (available at your local GM dealer of course) :)

98017958
Injector Connectors #2 and #7 Service Repair Kit


While you are at the dealer, ask them for a copy of this ( 05-06-04-047B ) bulletin. It has some graphics that will explain how to install the kit. The bracket for the #2 injector doesn't fit properly. I have e-mailed GM on this but no response. :cool:

[carco]

What Duramaster said! Mine had harness problems caused a lot of blue/white smoke and rough running. Warranty took care of it all. bob,,,,,,,,,,,,,,,

[mark45678]

injector wiring harness... mine did the same chit 2 years ago . make sure your buddie does both injectors that the bullitin spells out , mine got towed in for the second one 15 days after the first one craped out!

[Duramaster]

the kit comes as a "KIT" for both the number 2 and 7 injector connectors. The tech should have replaced both connectors! :confused:

[Claven]

Thanks for the replies, I'll pass it on and let you know how he makes out.