PicoScope 7 Automotive
Available for Windows, Mac, and Linux, the next evolution of our diagnostic scope software is now available.
Hi there! You seem to have a lot of knowledge under the hood. I'm really quite impressed by your graphs and terms. I'm a newbie so I honestly don't understand some of them. Anyway, I'm just wondering if you were able to solve your fluctuating rpm-gauge? Any updates about this because my friend is also encountering this kind of problem but a bit different. His rpm-gauge would go delay sometimes so we're kinda confused why is it like that. Do you have any opinion about that?joscorstjens wrote:My investigation started because my rpm-gauge was fluctuating heavily . It is connected to the wasted-spark ignition coil through 2 diodes and a zener diode on a pinto 2.0 injection engine.
I just measured cyl 1 secondary voltage (through capacitive pickup picoscopeprobe) which is going all over the place (from 1.5 up to > 20 kVolt) while the current through the primary coil is quite constant (from 4 to 7 amp) depending on the amount of dwell (2.3 to 4.4) I put in.
The attachments contain a view of the combined current and voltage reading on picoscope 4223 (third attach) the other two show a zoom of a lower voltage ignition spike.
The .psdata file seems too big to attach.
This pattern is similar on all 4 cylinders.
Injection and timing is ok and the car runs fairly well but a bit 'irregular'.
So what could be the cause of this?