TLDR - Need help with fuel rail pressure sensor, 6.6 swap in place of 5.3
This summer I swapped a 3-miles take-out 6.6 Gas L8T into our 2015 Suburban . The Suburban's 5.3 collapsed a lifter at 75K miles and was repaired under warranty. It collapsed another at 150K miles, so I made the change.
The L8T is a steel block with very similar architecture as the L83, but has ZERO displacement on demand (DOD) hardware. 80 additional cubic inches is great, too.
Doing this project myself was a major upgrade from what local shops were offering: 1. GM Crate swap for $17k or Jasper Reman swap for $9k. I'm in at about $9K now with new accessories, motor mounts, cooling system, tuning, etc. and ZERO DOD.
I have run into a final issue with tuning compatibility that the local tuner I am working with cannot quite help me sort out. The fuel rail pressure is reading ~3,500 psi at idle when is should be 580 psi. The tuner pointed back to the sensor being faulty and suggested the challenge is mechanical and not computer. I replaced the fuel rail sensor, found the same number and began digging in.
The fuel rail sensor for the 5.3 is a 4-prong sensor. The 6.6 sensor is a 3-prong. The fitting that connects to the fuel rail is different as well. The sensor plugs into the driver side injector harness. The main harness connection is mechanically the same, except that it is one-pin short.
After identifying the difference in sensors, the tuner shared that there isn't a programming work-around and the tuning software does not provide a table to calibrate this reading. The tuner states the 5.3 computer cannot interpret the 6.6 sensor in this instance. So we are at the first standstill of this otherwise straightforward project.
Have any of you experienced this? Is there a tuning workaround? Is the solution to replace the driver side fuel rail, injector harness, and sensor? If these parts are changed, will this cure this? I did not expect this to be uncharted territory, but apparently there are not many 6.6 swaps and this is a potential item.
This summer I swapped a 3-miles take-out 6.6 Gas L8T into our 2015 Suburban . The Suburban's 5.3 collapsed a lifter at 75K miles and was repaired under warranty. It collapsed another at 150K miles, so I made the change.
The L8T is a steel block with very similar architecture as the L83, but has ZERO displacement on demand (DOD) hardware. 80 additional cubic inches is great, too.
Doing this project myself was a major upgrade from what local shops were offering: 1. GM Crate swap for $17k or Jasper Reman swap for $9k. I'm in at about $9K now with new accessories, motor mounts, cooling system, tuning, etc. and ZERO DOD.
I have run into a final issue with tuning compatibility that the local tuner I am working with cannot quite help me sort out. The fuel rail pressure is reading ~3,500 psi at idle when is should be 580 psi. The tuner pointed back to the sensor being faulty and suggested the challenge is mechanical and not computer. I replaced the fuel rail sensor, found the same number and began digging in.
The fuel rail sensor for the 5.3 is a 4-prong sensor. The 6.6 sensor is a 3-prong. The fitting that connects to the fuel rail is different as well. The sensor plugs into the driver side injector harness. The main harness connection is mechanically the same, except that it is one-pin short.
After identifying the difference in sensors, the tuner shared that there isn't a programming work-around and the tuning software does not provide a table to calibrate this reading. The tuner states the 5.3 computer cannot interpret the 6.6 sensor in this instance. So we are at the first standstill of this otherwise straightforward project.
Have any of you experienced this? Is there a tuning workaround? Is the solution to replace the driver side fuel rail, injector harness, and sensor? If these parts are changed, will this cure this? I did not expect this to be uncharted territory, but apparently there are not many 6.6 swaps and this is a potential item.
