Finally tackled a Gen V

[Dewayne Smith]

Yelp, I've avoided them long enough so I finally took one on.

2014 GMC with a BTR Stave 3 V2 cam and headers. A transmission shop close to me called me in on this because the truck ran like crap. Before this truck the only thing I have done with Gen V is a DOD delete one time.
Anyway, someone else "tooned" this thing and let me tell you it sucked. -20 spark advance at idle, wouldn't stay running, 60% throttle @ 100% pedal, knock retard all over the place and over all just a turd.

I have it much better now but still a few areas I'm unsure of.

Spark advance, I have no experience with DI and simply don't know what they like for part throttle economy or WOT power. Seems to be working well where it is but I need to do a lot more testing. I wish I had taken time to look for a stock file to compare to or even just started from a stock file other than what the last guy had done.

Injector timing - on a Gen 3 or 4 I would be looking at exhaust valve closing at low RPMs and intake valve closing at higher RPMs. I hate to assume but As long as the SOI is at or after EVC I feel I should be good. I'll have to study up on this one a little more.

Fuel Pressure, Does the cam swap affect fuel rail pressure and if so what does this do for injector data? again, more research needed.


Now, This is something I have been fighting for a couple days now. I'm no stranger to AFR reading a little lean with a bigger camshaft and more overlap but this thing is constantly showing negative fuel trim at idle but my WB is showing lean. Everywhere else the WB and NBo2s seem to agree. Is this a product of DI or am I overlooking something stupid simple? This part is the main motivation for this post.

The attached tune is where I'm at right now and truck runs damn good. Still not really hearing the cam lope like I had hoped but I don't really care about that.
The log is just a short idle. It takes a little while for the WB to come in but once it does you can see that its showing lean but trim is pulling fuel.

Any advise would be greatly appreciated.Drew Pruitt norm 32.hptidle 32.hpl

[lucas287]

Bump. Also curious about the fueling problem as I’m experiencing something similar.