INDIVDUAL CYL IGN/FUEL TRIM AFTER FREQ. #1 CYL KNOCKS
Posted: Mon Jun 03, 2024 1:46 am
Hi @Hondata,
Here is the information about my vehicle:
i. Model: 10th generation Civic Non-Si 1.5T hatchback MT (China)
ii. Mileage: 12,000 kilometers
iii. Fuel: RON95/RON97
iv. Modifications: Sprint Filter P1078S, gently washed, cleaned, and dried every 2 months
v. FlashPro Calibration: Hondata +3psi calibration, with a customized* TC max pressure curve (adjusted to eliminate the kink around 2550rpm, gradually increasing to the peak point at 5500rpm as the +3psi calibration does)
vi. Weather: Around 27-37 degrees in the summer (now) with 80-90% humidity.
* PA 0.974/1.00
1.11842105263158
1.11842105263158
1.16447368421053
1.42368421052632
1.53684210526316
1.72092105263158
1.75815789473684
1.77447368421053
1.80815789473684
1.84763157894737
1.90065789473684
1.94736842105263
2.02276315789474
2.08381578947368
2.13684210526316
2.19697368421053
2.25
2.16842105263158
2.04342105263158
1.91184210526316
Concern/Issue:
I attempted to address my AFM issue due to the s.trim consistently ranging from -7% to -20%, with the l.trim fluctuating between -15%. Despite visiting my dealer for a sensor examination, all sensors were reported to be functioning correctly.
After numerous attempts involving 1-hour datalogs, I recalibrated my AFM multiple times. As a result, the s.trim now varies from 4% to -3%, while the l.trim consistently remains between -1% to 1%. Subjectively, I consider this adjustment to be "perfect." However, shortly after achieving what I deemed a successful recalibration, an issue arose.
While cruising at approximately 2000 rpm in 4th gear, a knock was detected in the #1 cylinder following a 15% throttle input, as indicated by my datalog. The K.control remained consistent at 54%, with K.retard gradually rising from 0% to 8% before reverting to 0% after a few seconds. Initially overlooking this occurrence due to the stable K.control, I later discovered a recurrent knock exclusively in the #1 cylinder at lower rpm ranges (1000-2000, across all gears), with no knocks experienced at WOT or higher RPMs.
Referring to the Hondata online manual, an uneven manifold intake was suggested as a possible cause of this issue, with a specific recommendation to adjust the ignition for a single cylinder. Consequently, I initiated a testing phase.
1st Adjustment:
~Ignition->Cylinder Trim->Individual Cylinder Ignition Trim
Cylinder | [1] | [2] | [3] | [4] |
Advance | [-1] | [0] | [0.5] | [0.5] |
~Fuel->Cylinder Trim->Individual Cylinder Fuel Trim
Cylinder | [1] | [2] | [3] | [4] |
Advance | [1] | [0] | [-0.5] | [-0.5] |
Outcome: Following a 26-minute cruise at 2000-3000 rpm, a total of 13 knocks were recorded, with K.control peaking at 60-65%. Notably, there were 8 knocks in #3, 1 knock in #1, 1 knock in #2, and 11 knocks in #3.
Based on the observed pattern and the suggested potential variances in fillings among cylinders, I proceeded with a new adjustment.
2nd Adjustment:
~Ignition->Cylinder Trim->Individual Cylinder Ignition Trim
Cylinder | [1] | [2] | [3] | [4] |
Advance | [-1] | [0] | [-1] | [0.5] |
~Fuel->Cylinder Trim->Individual Cylinder Fuel Trim
Cylinder | [1] | [2] | [3] | [4] |
Advance | [1] | [0] | [1] | [-0.5] |
Result: Following a 40-minute cruise at 2000-3000 rpm, including several WOT instances with 3rd and 4th gear, only 2 knocks were observed, both of which occurred in the #1 cylinder. One knock was noted at 1500 rpm in 3rd gear, and the other at 1500 rpm in 2nd gear, maintaining a constant K.control of 54% and K.retard gradually increasing from 0% to 8% before returning to 0%.
Considering the marked improvement in throttle response and controllability after the AFM recalibration, I am reluctant to revert to the original settings. Yet, I ponder further adjustments to individual cylinder fuel/ignition trims that are required to eliminate the knock in #1 cyl. Should I consider reducing the #1 cylinder's ignition by an additional -0.5 degrees while advancing #2 and #4 by 0.5 degrees? Furthermore, could additional fuel be beneficial for the #1 cylinder, and how should adjustments be made for the other cylinders?
Thank you,
Chris
Attachments:
Here is the information about my vehicle:
i. Model: 10th generation Civic Non-Si 1.5T hatchback MT (China)
ii. Mileage: 12,000 kilometers
iii. Fuel: RON95/RON97
iv. Modifications: Sprint Filter P1078S, gently washed, cleaned, and dried every 2 months
v. FlashPro Calibration: Hondata +3psi calibration, with a customized* TC max pressure curve (adjusted to eliminate the kink around 2550rpm, gradually increasing to the peak point at 5500rpm as the +3psi calibration does)
vi. Weather: Around 27-37 degrees in the summer (now) with 80-90% humidity.
* PA 0.974/1.00
1.11842105263158
1.11842105263158
1.16447368421053
1.42368421052632
1.53684210526316
1.72092105263158
1.75815789473684
1.77447368421053
1.80815789473684
1.84763157894737
1.90065789473684
1.94736842105263
2.02276315789474
2.08381578947368
2.13684210526316
2.19697368421053
2.25
2.16842105263158
2.04342105263158
1.91184210526316
Concern/Issue:
I attempted to address my AFM issue due to the s.trim consistently ranging from -7% to -20%, with the l.trim fluctuating between -15%. Despite visiting my dealer for a sensor examination, all sensors were reported to be functioning correctly.
After numerous attempts involving 1-hour datalogs, I recalibrated my AFM multiple times. As a result, the s.trim now varies from 4% to -3%, while the l.trim consistently remains between -1% to 1%. Subjectively, I consider this adjustment to be "perfect." However, shortly after achieving what I deemed a successful recalibration, an issue arose.
While cruising at approximately 2000 rpm in 4th gear, a knock was detected in the #1 cylinder following a 15% throttle input, as indicated by my datalog. The K.control remained consistent at 54%, with K.retard gradually rising from 0% to 8% before reverting to 0% after a few seconds. Initially overlooking this occurrence due to the stable K.control, I later discovered a recurrent knock exclusively in the #1 cylinder at lower rpm ranges (1000-2000, across all gears), with no knocks experienced at WOT or higher RPMs.
Referring to the Hondata online manual, an uneven manifold intake was suggested as a possible cause of this issue, with a specific recommendation to adjust the ignition for a single cylinder. Consequently, I initiated a testing phase.
1st Adjustment:
~Ignition->Cylinder Trim->Individual Cylinder Ignition Trim
Cylinder | [1] | [2] | [3] | [4] |
Advance | [-1] | [0] | [0.5] | [0.5] |
~Fuel->Cylinder Trim->Individual Cylinder Fuel Trim
Cylinder | [1] | [2] | [3] | [4] |
Advance | [1] | [0] | [-0.5] | [-0.5] |
Outcome: Following a 26-minute cruise at 2000-3000 rpm, a total of 13 knocks were recorded, with K.control peaking at 60-65%. Notably, there were 8 knocks in #3, 1 knock in #1, 1 knock in #2, and 11 knocks in #3.
Based on the observed pattern and the suggested potential variances in fillings among cylinders, I proceeded with a new adjustment.
2nd Adjustment:
~Ignition->Cylinder Trim->Individual Cylinder Ignition Trim
Cylinder | [1] | [2] | [3] | [4] |
Advance | [-1] | [0] | [-1] | [0.5] |
~Fuel->Cylinder Trim->Individual Cylinder Fuel Trim
Cylinder | [1] | [2] | [3] | [4] |
Advance | [1] | [0] | [1] | [-0.5] |
Result: Following a 40-minute cruise at 2000-3000 rpm, including several WOT instances with 3rd and 4th gear, only 2 knocks were observed, both of which occurred in the #1 cylinder. One knock was noted at 1500 rpm in 3rd gear, and the other at 1500 rpm in 2nd gear, maintaining a constant K.control of 54% and K.retard gradually increasing from 0% to 8% before returning to 0%.
Considering the marked improvement in throttle response and controllability after the AFM recalibration, I am reluctant to revert to the original settings. Yet, I ponder further adjustments to individual cylinder fuel/ignition trims that are required to eliminate the knock in #1 cyl. Should I consider reducing the #1 cylinder's ignition by an additional -0.5 degrees while advancing #2 and #4 by 0.5 degrees? Furthermore, could additional fuel be beneficial for the #1 cylinder, and how should adjustments be made for the other cylinders?
Thank you,
Chris
Attachments: