Misfire ls1 5.7 on acceleration and at higher rpm

[Kane]

Hi there ,
Fairly new to the tuning side of things , I have a Holden commodore ls1 5.7 in a 96 Silverado .
For the most part runs fine . It was adding quite a bit of fuel on the long term fuel trims . I found a small air leak and have correct this which made it a lot better . Then I added another 10 points to the airflow table and I have the fuel pretty close now on the fuel trim log when driving .
I have done around four similar conversions . But all of these conversations all seem to break down under load or high rpm? Popping back thru the intake . It seems to be a common thing .
Almost like an hi lead or coil breaking down . We have chased them and replaced them etc etc .
Still can?t get rid of the misfire .
Do the lifters pump up on these engines causing a misfire , any help would appreciated

[Frost]

Make sure that your CPS is 100% an OEM sensor and not a "parts store" sensor. I've fixed more than 5-6 that had upper RPM issues from the awesome Chinese sensors that were installed.

[Kane]

Great thanks for advice , I’ll check sensor
Cheers kane