L92 E38 swap hard starting

[XSKIER]

I've swapped an L92 with livernois L92 stage 2 cam into an 07 5.3 avalanche. I used the perfectly functioning E38, sensors, and wiring from the LC9 5.3, and the intake, map, and injectors from the L92. I have long tube headers into a Y, with an AEM wideband AFR after the Y. First, I'm thinking that my flow verses pressure table must be off, but I don't really know how this part of the tune is figured. Second, the engine will not start without at least 35% throttle. Once running, it does idle acceptably and afr hovers around 14.5-15. While cruising the afr will stay real near 14.7, but any thing over 3500 RPM it drops to 9.5 - 10. Consequently, I do get a CEL for bank 1 and 2 too rich. What should I try to lean this thing out?
hot start 6.2.hpl
2007 AVALANCHE 6.2 initial.hpt

[5FDP]

The MAP sensor should not read 83kpa when the vehicle is KOEO, it should read nearly 100-105kpa.

If you used injectors from the L92 you need to copy over the flow rate vs pressure table over if you haven't.

It's going to need a lot of VVE and MAF tuning but right now the to me the MAP sensor is throwing alot of this off right now.

Also are you running E85 or pump gas?

Because your alcohol content is saying you are running 35% E content. If that is not true you need to disable the virtual flex fuel sensor.

[NJ_Phil]

Nice find on the low kPa.. Unless he's tuning on Mars.

I think your startup airflow (1st 8 seconds) is way too low causing a lean start, then your Idle base airflow is way too high causing it to go pig rich

[XSKIER]

Good catch on the alcohol %. Pump fuel around here is 10%-15% ethanol, so it is ok to disable the Flex Fuel? I don't have the injector table from the donor ECM, but I assume that any L92 table floating around on the net will be ok? I did try and raise the idle Airflow Final Minimum by alot thinking it could help, should I copy this from the L92 as well? On the MAP sensor, Should I replace it, or can it be calibrated?

[5FDP]

What year harness and sensor is the MAP??

The LC9 motor in my 2012 Silverado has different MAP linear and offset settings compared to what your truck is running. Mine are 128 and -0.30. If the harness is newer than yours, it's likely the settings that I have.

Fuel here in Minnesota is up to 10% E content, it always varies from 3-8% for the most part so I just disabled my Flex fuel feature. Besides it's not accurate whatsoever, it's not even a real sensor. All it does is guess at the alcohol content based on o2 sensor readings, so it's basically pointless.

Not every L92 tune could be the same for injector data, there may be a difference if one is flex fuel and the other is not. You'll need to grab the part number off the injectors if you don't know and look up how large they are at 4 BAR/58 psi. Non flex fuel injectors are like 15-20lb/hr smaller.

[XSKIER]

My harness is the 07 LC9. The L92 MAP plug is different, so I just cut the plug of the L92 harness and spliced it onto the LC9 harness. Maybe the wire pin assignments are different? The three wire colors are the same. I will investigate this also.

[XSKIER]

Before I change the MAP offset, I see the barometric pressure reading is 12.0 or 82.7 kpa in that initial log. Is the barometric reading calculated from the MAP, or is there another sensor to it?

[XSKIER]

Ok, so I copied and pasted the injector info, MAP info, and spark tables. It still won't start with no pedal. I then set 600 to 800 base spark to 15, in an effort to reduce loping idle, and set base cranking spark to 15 in an effort to get it to start faster. No Luck.

13 sierra 6.2 mod.hpl

2007 AVALANCHE 6.2 13mod.hpt

[Jon S.]

My harness is the 07 LC9. The L92 MAP plug is different, so I just cut the plug of the L92 harness and spliced it onto the LC9 harness. Maybe the wire pin assignments are different? The three wire colors are the same. I will investigate this also.

The 2007 LC9 used a Delphi MAP. Sounds like the L92 was newer, and used a Bosch MAP.

If you married the wires by COLOR, you should be OK.

Delphi MAP:
- Pin A is an orange / black wire (J2 pin 53)
- Pin B is a light green wire (J2 pin 58)
- Pin C is a grey wire (J2 pin 43)

MAP Sensor Linear: 94.4297 kPa
MAP Sensor Offset: 10.3359 kPa


Bosch MAP:
- Pin 1 is a grey wire (J2 pin 43)
- Pin 2 is an orange / black wire (J2 pin 53)
- Pin 3 is a light green wire (J2 pin 58)

MAP Sensor Linear: 128.2031 kPa
MAP Sensor Offset: -0.3047 kPa

[Jon S.]

... I don't have the injector table from the donor ECM, but I assume that any L92 table floating around on the net will be ok? ...

Need to copy the values from a 2009+ L92 tune.

[5FDP]

I'd stop going full throttle on an un-finished tune, also you aren't even logging knock.

It's for sure going to take some playing with idle airflow tuning and fully tuning the VVE and MAF curve for the changes made. It's going to take some time to tune these things in, nothing can be just plug and play to make it start up and run perfect.

[XSKIER]

The 2007 LC9 used a Delphi MAP. Sounds like the L92 was newer, and used a Bosch MAP.

If you married the wires by COLOR, you should be OK.

Delphi MAP:
- Pin A is an orange / black wire (J2 pin 53)
- Pin B is a light green wire (J2 pin 58)
- Pin C is a grey wire (J2 pin 43)

MAP Sensor Linear: 94.4297 kPa
MAP Sensor Offset: 10.3359 kPa


Bosch MAP:
- Pin 1 is a grey wire (J2 pin 43)
- Pin 2 is an orange / black wire (J2 pin 53)
- Pin 3 is a light green wire (J2 pin 58)

MAP Sensor Linear: 128.2031 kPa
MAP Sensor Offset: -0.3047 kPa

Thanks, for the investigation. That is exactly how it is set up now.

[XSKIER]

I'd stop going full throttle on an un-finished tune, also you aren't even logging knock.

It's for sure going to take some playing with idle airflow tuning and fully tuning the VVE and MAF curve for the changes made. It's going to take some time to tune these things in, nothing can be just plug and play to make it start up and run perfect.

Yeah, but the temptation is too great! I am watching the AFR like a hawk while doing so. One thing I noticed on this last spin was that the scanner showed the ECM going into open loop on deceleration, meanwhile the AFR gauge was 18+.

[5FDP]

Likely going into DFCO and that shuts off fuel/spark so seeing the wideband go lean like that is normal.

[XSKIER]

I don't see a place for it, but is there some way on the E38 to command 30% throttle at startup? Why does my stock 2015 SS Sedan roar to life and then quickly simmer down? Newer ECM with more tun-ability?

[XSKIER]

Ok, so I read the stock tune from my 2017 L96. The cranking spark table is much larger, and has more advance to it. I may try to add some of that to the 2007 L92.

[XSKIER]

https://youtu.be/bcrRUDtYrOc

Ok, I got it to start with no pedal by adjusting the start up minimum airflow. Now I just need to get it to hit my target 780 idle in less than one minutes time. Maybe like 10 seconds on a hot motor?