 |
This is a good waveform |
| Vehicle: |
Aston Martin V8 |
 View larger image
 Download this waveform file for use with PicoScope
Triple Spark Waveform Notes
The triple spark replaces the usual single shot spark found on most systems. The idea is to use 3 sparks in quick succession to improve combustion by lowering the idle and decreasing low rpm emissions. The triple spark is replaced by the usual single spark once a preset rpm is reached – usually in the region of 2500 rpm. Triple spark is used mainly on large CID V8 engines.
This waveform was captured on a big V8 engine at idle, using coil-on-plug configuration (8 separate coils). Each coil is individually controlled by the PCM. The waveform was captured using a 2-channel PicoScope automotive oscilloscope in conjunction with our coil-on-plug ignition HT probe.
So what can we see in the waveform? Well, notice that the first 2 sparks are of a shorter than usual duration – the pcm re-energises the coil after less than 1 ms of burn time, to top-up the charge in the coil, then switches off the current again to produce another spark at the plug. On the last spark, the full stored energy in the coil is used, finishing up with the usual coil oscillations caused by the last drop of energy left in the coil when the spark dies ringing away into the coil’s internal impedance.
Testing the system is done coil-by-coil, using the coil-on-plug probe. The general form of the pattern is checked in the usual way, but lift the engine rpm and confirm that the system switches over to single spark at the same rpm at each coil, and that the pattern is stable and consistent through the rpm range of the motor with no misfiring.
汽車診斷 | 汽車診斷儀 | 汽車故障診斷儀 | 汽車測試儀 | 汽車分析儀 | 汽車診斷示波器 | 汽車電路測試儀 | 汽車電路分析儀 | 發動機分析儀 | 發動機綜合分析儀 | 發動機檢測中心 | 點火分析儀 | 點火測試儀 | 汽車傳感器測試儀 | CAN總線示波器 | LIN總線示波器 | 汽車故障記錄儀 | 汽車傳感器分析儀 | 汽車檢測儀 | 噴油嘴測試儀 | 點火線圈測試儀 | 蓄電池測試儀 | 發電機測試儀 | 起動機測試儀 | ABS傳感器測試儀 | ECU測試儀 | ECM測試儀 | 進氣真空/壓力測試儀 | 排氣壓力測試儀 | 汽車技術培訓 | 爆震傳感器測試儀 | 缺火測試儀 | 缺缸測試儀 | 線路測試儀 | 引出線 | 汽車數字示波器 | 真空傳感器 | 高壓感應測試頭 | 無分電器點火測試頭 | 獨立點火（COP）感應測試頭 | 漏電測試儀 | 氣缸相對壓縮測試 | 電腦測試儀 | 發動機控制器測試儀 | 泄漏測試儀 | 熒光檢漏 | 超聲波檢漏 | 汽車數字萬用表 | 電流鉗表 | 電流勾表 | 點火正時燈 |
