• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

LMM 1 cylinder high injector pressure only when cold and smokes

Builder1972

New Member
Messages
7
Reaction score
1
Location
United States
I have a 2010 LMM Duramax. When the truck is below 180 +- deg. It idles rough and has one injector pressure (#8) at about 7mm. It smokes really bad as well. Once it’s warm it runs great. New injectors. And I took the one injector (8)with high rate and switched it with another (6) and problem stayed in original (8)cylinder. New ECM, new GPCM , new map sensor . EFI Live , dpf delete, EGR is still on just inactive. Somebody please help !
 

Jaryd

Extremely Deplorable
Messages
1,675
Reaction score
2,676
Location
Hodges, SC
Sorry, can’t help with the issue but when FERM sees this thread he can probably help you out.
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
Messages
10,054
Reaction score
4,309
Location
ZEPHYRHILLS FL
Which injector exactly did you swap? Front or rear on passenger side or drivers side? Did you use a tech 2 to program the new injector flow rates?

And the number you're seeing has nothing to do with pressure, it's the balance rate. That is how far +/- from the fuel rate each 8njector is injecting.
 

Builder1972

New Member
Messages
7
Reaction score
1
Location
United States
The issue is with injector 8 had 3 different injectors in that hole. All the same. Rates aside. When that number goes up after about 20 seconds or so. The truck runs a little rough and starts smoking a lot. Coolant levels good oil level is good. And yes recalibrated everything with tech2
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
Messages
10,054
Reaction score
4,309
Location
ZEPHYRHILLS FL
Which cylinder are you calling #8? I've seen many mess up and keep swapping #7 not realizing the DURAMAX's cylinder ordering is different from other GM engines. Even seen guys at the dealership make this mistake, thats why I'm asking.
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
Messages
10,054
Reaction score
4,309
Location
ZEPHYRHILLS FL
Just making sure, you would be surprised how many swear #1 is the front drivers side. I would be doing a compression test if it was mine..
 
Top