Stumble at High Load
04-05-2024, 09:07 AM
#1
Stumble at High Load
Hello all, I have a 99 silverado RCSB with an LQ4 swap. Factory heads, intake and injectors. Summit 8720r1 cam. I have tried tuning changes, different injectors, coils, and wires. Pulled the plugs and they look new with stock gap around .045. What happens is, anytime I am at high load, 90kpa or higher, I get an occasional stumble. This occurs at both low rpm high load and high rpm WOT and everywhere in between. The common denominator is the load. Happens in both closed loop and PE closed loop fueling. I almost want to say it either has to be plug gap or something internally wrong with the engine. Let me know if anyone has any thoughts on this.
04-05-2024, 09:20 AM
#2
TECH Resident
Hello all, I have a 99 silverado RCSB with an LQ4 swap. Factory heads, intake and injectors. Summit 8720r1 cam. I have tried tuning changes, different injectors, coils, and wires. Pulled the plugs and they look new with stock gap around .045. What happens is, anytime I am at high load, 90kpa or higher, I get an occasional stumble. This occurs at both low rpm high load and high rpm WOT and everywhere in between. The common denominator is the load. Happens in both closed loop and PE closed loop fueling. I almost want to say it either has to be plug gap or something internally wrong with the engine. Let me know if anyone has any thoughts on this.
If you can consistently replicate the issue, a run/record log on HP Tuners and post it here. I'm sure folks savy with tuning can review it for you...
Last edited by strutaeng; 04-05-2024 at 01:53 PM.
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reubone (04-05-2024)
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