- Wed May 31, 2023 12:58 am
#63293
Ignition timing shifts between cylinders.
I am posting for the first time from Japan. The car is a 1972 Suzuki Kei-car Fronte Coupe, 2 stroke 3 cylinder 360cc engine.
I've had my Speeduino for over 2 years and it runs fine. However, recently I noticed a discrepancy in ignition timing between cylinders.
The situation is below.
No. 1 cylinder timing (crank angle = 0 degrees) .... #1_cylinder timing.jpg
No. 2 cylinder timing (crank angle = 240 degrees) .... #2_cylinder timing.jpg
No. 3 cylinder timing (crank angle = 120 degrees) .... #3_cylinder timing.jpg
*ch1-ignition signal ch-2 crank angle signal (pulley: 6-1)
*Engine speed is at 6000rpm.
*The crank angle signal is an accurate pseudo signal generated by the Pulse Generator.
The time between the falling edge of each ignition signal (ignition here) and the immediately following crank angle signal should be equal. However, the observation results are as follows.
Cylinder #2 lags behind #1 by about 100usec, and cylinder #3 lags behind #1 by about 50usec. This corresponds to an angular delay of about 2 to 4 degrees.
Below are some supplementary information.
・The injector signal does not have such a timing shift.
・The firmware version is a bit old 202108, but the latest version 202305 was the same.
- Attach CurrentTune.msq.
Please let me know if anyone has any information about this inconvenient phenomenon.
Thank you.
Shinji
I am posting for the first time from Japan. The car is a 1972 Suzuki Kei-car Fronte Coupe, 2 stroke 3 cylinder 360cc engine.
I've had my Speeduino for over 2 years and it runs fine. However, recently I noticed a discrepancy in ignition timing between cylinders.
The situation is below.
No. 1 cylinder timing (crank angle = 0 degrees) .... #1_cylinder timing.jpg
No. 2 cylinder timing (crank angle = 240 degrees) .... #2_cylinder timing.jpg
No. 3 cylinder timing (crank angle = 120 degrees) .... #3_cylinder timing.jpg
*ch1-ignition signal ch-2 crank angle signal (pulley: 6-1)
*Engine speed is at 6000rpm.
*The crank angle signal is an accurate pseudo signal generated by the Pulse Generator.
The time between the falling edge of each ignition signal (ignition here) and the immediately following crank angle signal should be equal. However, the observation results are as follows.
Cylinder #2 lags behind #1 by about 100usec, and cylinder #3 lags behind #1 by about 50usec. This corresponds to an angular delay of about 2 to 4 degrees.
Below are some supplementary information.
・The injector signal does not have such a timing shift.
・The firmware version is a bit old 202108, but the latest version 202305 was the same.
- Attach CurrentTune.msq.
Please let me know if anyone has any information about this inconvenient phenomenon.
Thank you.
Shinji
Attachments
(82.29 KiB) Downloaded 2454 times
messageImage_1671876066811.jpg (195.49 KiB) Viewed 12459 times
#1_cylinder_timing.jpg (284.38 KiB) Viewed 12459 times
#2_cylinder_timing.jpg (297.42 KiB) Viewed 12459 times
#3_cylinder_timing.jpg (284.12 KiB) Viewed 12459 times