Eliminate TCM

[thetallengineer]

I have a new problem with the installation of my LBZ duramax and starting. With the dyno disconnected, the engine starts up effortlessly and runs nicely. However, with the dyno attached it starts sluggishly and does not make it above 400 RPM. It injects about 42-48 mm^3 of fuel during this time, whereas with the dyno disconnected it only injects about 3-6 mm^3 of fuel.

The voltage to the dyno is disconnected so there is no load placed on the engine other than the inertia of the rotating assemble within the dyno. The dyno shaft can be turned by hand so I don't think it is an issue with corrosion inside or a bad bearing.


Is it possible to use EFI Live to eliminate the need for a TCM? My concern is that the TCM is communicating with the ECM and somehow interfering.

[GMPX]

Probably the only option here is to use a calibration from a manual transmission, no TCM then!

Cheers,
Ross

[thetallengineer]

My understanding is that the 2006 LBZ trucks were only offered with the automatic and that you need a LLY calibration to use as a basis for the change?

Is this correct? Anyone successfully done this with a stock calibration?

[thetallengineer]

What is weird is that when I watch the Main Injection quanity, for the first 2-3 seconds after it initially fires, I see it maxing out fuel in an effort to raise RPM. Then after that time period it cuts fuel to zero. So it appears as if it is failing some sort of check when the small inertia load of the dyno is present and decides to cut fuel to turn off the engine.

The inertia load is approximately 75 lb-ft^2. Previous generation Duramax engines have been coupled to dynos with around 100 lb-ft^2 of inertia and ran fine. However they may have been using ECMs programmed for test cell use and lacked any type of commercial calibration or checks & balances.

[GMPX]

My understanding is that the 2006 LBZ trucks were only offered with the automatic and that you need a LLY calibration to use as a basis for the change?

Is this correct? Anyone successfully done this with a stock calibration?

I learnt something today with regards to no manual on the LBZ!, I just assumed I'd never seen a file because they were rare. Well, if the LLY can do it, then there is no reason the LBZ couldn't given it's the same ECM.
Currently we only show the transmission type for your reference, but that can be altered. I don't actually know if it would be as simple as switching that parameter to manual and have everything just work. But, I guess at the moment you are willing to try anything!.
Shoot me a PM

Cheers,
Ross