LB7: Fuel Trim

[daltongd]

2002 LB7 all stock, 2002 with 213K miles. Recently replaces all (8) injectors and then got a fuel rail pressure code so I replaced the fuel pump and regulator. After getting it running again, it felt like the transmission would jump into neutral right after shifting into 2 or from 2 to 3. It only happened momentarily and it didn't happen all the time. It also didn't seem to do it when I gave it some throttle. I drove it for a while hoping it would just go away and then took it to a transmission mechanic. He said the PCM is trimming fuel and the transmission is just fine. Any idea what he is talking about when he says trimming fuel on a diesel.

I do have a code that says the glow plugs have a high voltage but that's it.

 

[S Phinney]

Sounds like you are describing a trans flair. The mechanic doesn't seem to be accurate. Does it continue to do it? How long has it done it for now? Your truck will act differently until the TCM get adjusted to the new fueling/torque differences coming from better fueling with your parts changes.

 

[daltongd]

I ended up taking it to a mechanic and he found a fuel leak. The return line from the CP3 had a pin hole. I have repaired that but the problem is still there.