Om du kan visa strömmen som går till spriderna på ett oscilloskop så går det att se om och när spriderna öpnnar sig. Då kan du se om nån av spridare är trögare än de andra eller hakar upp sig ibland.
Om man inte har en strömsensor kan det väll inte vara svårt att göra en shunt/strömadapter med spridarkonkater för att visa strömmen på oscilloskopet?
The voltage waveform can show basic faults in the injector coil and the ECU, but it can’t find a stuck injector. A few vehicles have injector-position sensors, but generally you can check by measuring the injector current. If you have an automotive PC oscilloscope, just select the “injector (current)” option from the menu and follow the instructions. The two-pin breakout lead is handy here, as you can clamp the current probe on it without disturbing the vehicle’s wiring.
The current waveform has a vertical scale of thousandths of an amp (milliamps or mA), and the same time scale as the voltage waveform. At time zero, the ECU switches the injector on. The current rises smoothly to about 850 milliamps, until the ECU switches the injector off.Notice the small dip in current at 1 ms — this is when the injector opens. Only the current waveform shows you this. If there is no dip, the injector is stuck.
If the dip is later on one injector than on the others, that injector is slow, causing the cylinder to run lean.
If the current pulse is rectangular instead of curved, the injector is shorted.
No current means the injector coil is probably open-circuit.