traiblazer e67 ly6 swap help

[jsusnaim]

Hi, im having issues with my traiblazer lh6. i just swapped it to a ly6 and im having lots of issues, it needs several cranks to turn on, also when i put light throttle into it it accelerates as it should. but when i give it throttle wot or more than 50% it backfires like crazy, i dont know where to start diagnosing. im posting a log and my lastest tune.

idles perfectly.
map indicates 53kpa switch on (idk if fault is map related)
other than that everything seems ok

any help you can give me. i will appreciate it

Sorry for my bad english!lh6 tune stock test 1.hptly6 swap e67 issue.hpl

[blindsquirrel]

What parts did you use from the LY6 and which were reused from the LH6? Injectors, throttle body, MAP, etc.

[jsusnaim]

What parts did you use from the LY6 and which were reused from the LH6? Injectors, throttle body, MAP, etc.

i did use the stock throttle body injector and map sensor.

[blindsquirrel]

Stock for which?! Stock for the LY6 or stock for the 2007 Trailblazer?

[jsusnaim]

Stock for which?! Stock for the LY6 or stock for the 2007 Trailblazer?

stock lh6, throttle body, and injectors.

[blindsquirrel]

Well I see it idling at 25-28 kPa MAP, and I suspect that's physically impossible. Are you sure it has the MAP sensor original to the truck? Because if your LY6 is a 2009 or newer it has a different MAP sensor, both externally/fitment-wise, and also different electrically. If you have the 2009-up MAP that has linear/offset of 128.20/-0.030 but have the tune file set up with the original MAP's settings of 94.43/10.34, that would explain both the bad running complaints and the super-low kPa at idle.

If you still have the stock LH6 injectors why does that file not have stock LH6 injector data in it? It looks like some of the data was just changed at random for no reason.

[jsusnaim]

Well I see it idling at 25-28 kPa MAP, and I suspect that's physically impossible. Are you sure it has the MAP sensor original to the truck? Because if your LY6 is a 2009 or newer it has a different MAP sensor, both externally/fitment-wise, and also different electrically. If you have the 2009-up MAP that has linear/offset of 128.20/-0.030 but have the tune file set up with the original MAP's settings of 94.43/10.34, that would explain both the bad running complaints and the super-low kPa at idle.

If you still have the stock LH6 injectors why does that file not have stock LH6 injector data in it? It looks like some of the data was just changed at random for no reason.

thats me just trying to trouble shoot lol. i kept the stock traiblazer 5.3 wiring and maf sensor. its a stock 3 bolt cam from a lq4

[blindsquirrel]

MAP. Manifold Absolute Pressure, not Mass Airflow Sensor. The one that reads the vacuum. What is the number on it? Is there anything I can do to make this easier to understand?

screenshot.06-02-2024 19.52.55.png

[jsusnaim]

MAP. Manifold Absolute Pressure, not Mass Airflow Sensor. The one that reads the vacuum. What is the number on it? Is there anything I can do to make this easier to understand?

screenshot.06-02-2024 19.52.55.png

im using the left one. the one without the hole.

[blindsquirrel]

Then you have some other problem somewhere not in the tune file. 53 kPa at key on is wrong, it should be around 100 kPa. Idling at 25 kPa is wrong, idle with a stock cam should be around 40 kPa. Nothing in the tune other than the linear/offset can make the MAP read wrong.