05 chevy avalanche, p0068

[arriazolacricri]

hello, i cant get my truck to stop throwing the p0068, ive read a lot of forums and i just cant figure it out. its a 6.0 with turbo 10psi, walbro fuel pump and decapped flex fuel injectors on e85. also when i floor it all power cuts out around 5000 rpm.my avalanche 6.0 22 e85.hptavalanche cuts out 1 track.hpl

[kevin87turbot]

Did you start with a flex fuel calibration file? The commanded AF ratio seems to indicate that you're on gas.
The VE table has some very high values. That will contribute to the P0068 DTC.

[arriazolacricri]

Did you start with a flex fuel calibration file? The commanded AF ratio seems to indicate that you're on gas.
The VE table has some very high values. That will contribute to the P0068 DTC.

i removed my flex fuel sensor cause it was faulty, and all i run is e85 now, what do you recommend i do to dial in my fueling?

[Lakegoat]

If you are running E85 ONLY, your Stoich table should be 8.77099 in all cells. Under Power Enrichment, Boost Eq should be approx 1.27 across. You get your fueling correct by using your wideband and correcting the VE table. Commanded numbers are just a reference so you can adjust fueling until it matches commanded. I can imagine that when you floor it, you have enough fuel to drown it according to the VE table. However, with one pump and running E85, you might be running out of fuel pressure. Check your pressure and log injector duty in channels.

[arriazolacricri]

If you are running E85 ONLY, your Stoich table should be 8.77099 in all cells. Under Power Enrichment, Boost Eq should be approx 1.27 across. You get your fueling correct by using your wideband and correcting the VE table. Commanded numbers are just a reference so you can adjust fueling until it matches commanded. I can imagine that when you floor it, you have enough fuel to drown it according to the VE table. However, with one pump and running E85, you might be running out of fuel pressure. Check your pressure and log injector duty in channels.

This is my first time boost tuning, I thought after should be around 11.5 to 10.5, u will definitely try what you said to see if it works!! I grabbed a fuel gauge and it stays at 70psi under boost.

[arriazolacricri]

If you are running E85 ONLY, your Stoich table should be 8.77099 in all cells. Under Power Enrichment, Boost Eq should be approx 1.27 across. You get your fueling correct by using your wideband and correcting the VE table. Commanded numbers are just a reference so you can adjust fueling until it matches commanded. I can imagine that when you floor it, you have enough fuel to drown it according to the VE table. However, with one pump and running E85, you might be running out of fuel pressure. Check your pressure and log injector duty in channels.

what would you recommend i do with my ve tables for now?

[blindsquirrel]

what would you recommend i do with my ve tables for now?

Other than logging wideband data for commanded vs. actual and then applying that error data to the VE (this is also known sometimes as 'tuning')? Or is this a trick question?

[arriazolacricri]

i wanted to know like what numbers should i start with for now for it to be decent..

[RDF1]

I always start by dialing in all the 0-105 Kpa cells.. Once that is done then move over to the 105 Kpa+ cells. only go a little at a time.
Easiest way is to start out by barely getting into boost.. 105-120kpa and get that tuned.. then 120-150kpa.. Take baby steps. Sure its time consuming but better than popping a piston and having to pull engine.

I use to hook to a heavy trailer and tune the low rpms higher boost cells in my tow truck