2016 6.2 Stall and Hard Starting After Tune

Any help would be appreciated. Have a 2016 6.2 gm truck with Procharger installed. Original flash was Diablosport and truck ran decent except for WOT where there heavy stumbles on shifting.

Just built a new EFI Live tune for both the E92 ECM and T87 TCM, an expert tuner helped me. TCM tune was stock and flashed very nice. The ECM Diablosport tune was another story. I had the checksum issues and stranded me at a parking lot for about an hour with a ECM with no calibration. V7.5 would not allow me to flash it either since the ECM with checksum error could not be read.

Was told to go into the new tuning file and access the red folder with the V2 connected to the vehicle and change the checksum to 65535. I did this, tried a cal-flash and finally the truck accepted the tune successfully however it still would not start. Retried with a full flash, then the truck started. As I put the truck in gear and started to drive it stalled. Upon cranking, it fires intermittently but struggles to start. Ignition cycling and modulating the accel pedal like crazy got it going eventually. But in order to keep it running you have to keep it well above 1500 RPMS. Then driving I have to manually shift it to keep the RPMs high because if I leave it in D, when I slow down the engine stalls and won't restart without the ignition cycling and accel pedal pumping.

Wondering if this is a VATS issue or a table that needs adjusting like idle speed?

The old Diablosport tune that ran well overall had slightly higher idle in the tables, on average about 100 RPM.

Any thoughts on this?

Quote:

---

Originally Posted by Abesstorage

Any help would be appreciated. Have a 2016 6.2 gm truck with Procharger installed. Original flash was Diablosport and truck ran decent except for WOT where there heavy stumbles on shifting.

---

Did you ever read out the DS tune (using EFILive)...?

Quote:

---

Just built a new EFI Live tune for both the E92 ECM and T87 TCM, an expert tuner helped me. TCM tune was stock and flashed very nice. The ECM Diablosport tune was another story. I had the checksum issues and stranded me at a parking lot for about an hour with a ECM with no calibration. V7.5 would not allow me to flash it either since the ECM with checksum error could not be read.

---

Are these the tunes (ECM and TCM) that struggle to start, stalls, require accelerator peddle input, and won't run below 1500 rpm, and trans requires manually shifting...?

How far from stock are these tunes (how many tables were edited, was it tuned for the SC properly)...?

Quote:

---

Was told to go into the new tuning file and access the red folder with the V2 connected to the vehicle and change the checksum to 65535. I did this, tried a cal-flash and finally the truck accepted the tune successfully however it still would not start. Retried with a full flash, then the truck started. As I put the truck in gear and started to drive it stalled. Upon cranking, it fires intermittently but struggles to start. Ignition cycling and modulating the accel pedal like crazy got it going eventually. But in order to keep it running you have to keep it well above 1500 RPMS. Then driving I have to manually shift it to keep the RPMs high because if I leave it in D, when I slow down the engine stalls and won't restart without the ignition cycling and accel pedal pumping.

---

Can you give more details, what was preventing it from flashing (do you have the log text)...?

Quote:

---

Wondering if this is a VATS issue or a table that needs adjusting like idle speed?

---

VATS would let it crank but would prevent it from running.

Sounds very much like you need to start from stock and get tuned properly.

Quote:

---

The old Diablosport tune that ran well overall had slightly higher idle in the tables, on average about 100 RPM.

---

Did you ever read out the DS tune (using EFILive)...?

It wound up being the MAP scaler, it was way off. Truck is running well.

ok, thanks, that would explain it.