Injector replace

[garyr]

Could I have injector problem and no smoking? As Low psi on couple of injectors

[DmaxMaverick]

The high pressure fuel system is common rail, so all injectors should have the same PSI. However, injectors can fail absent of smoke evidence. What did you find that brought the question?

[garyr]

I'm not really sure mech said I had low pressure at 2 injectors he showed me on screen while truck is running. What my truck is doing while at idle surging it's like a gas burner with large cam. And fuel mileage has dropped slightly.

[Kennedy]

The LLY injectors have been the most reliable of any Dmax to date. A surge/rolling idle is typically caused by a failing pressure regulator or major air in the system.

[More Power]

Could I have injector problem and no smoking? As Low psi on couple of injectors

You may be referring to "fuel rate". Balance is achieved when all 8 injectors produce a fairly low deviation from one another. I just had the injectors replaced in my LB7. The #2 injector was way out of tolerance, and was consistently setting P0302.

The FPR in my truck has always caused a small amount of surging at idle - it has done this for 100K miles. GM specifies a +/- 100 rpm or less at idle as not being a warrantable defect. Most Duramax fuel systems produce surge values lower than 100. I've not worried too much about the surge in my truck....

[Kennedy]

You are probably 90% of the way there (regulator labor) when doing an injector job ;)