Depending on the coil design/insulation often times a regular probe will capture a signal that allows to measure burn time, at least. Even without coin. Although you only get a fraction of the information the secondary can offer at least it allows a relative comparison between coils/cylinders.
An expert is someone who knows each time more on each time less, until he finally knows absolutely everything about absolutely nothing.
Wow this thread really picked up since I was last here.
I believe the attenuation is for a few reasons. One, liability. They don't want to be buying you new oscilloscopes when a spark jumps to the probe or if the voltage output becomes to high and overloads your scope or your scope settings can't be set high enough to get the entire waveform in view.
The pico probe may also work better with the Pico scope. I've never tried.
The improvised probes, well your dancing with the devil but honestly I've been using my liquid tape coated coil of wire for a long time now without issues. I find shielding in the coil is tough with professional probes and sometimes even with the improvised probes.
I've used coils of solder wrapped in electrical tape on top of multiple coils, or solder wrapped around ignition wires, (Hopefully good wires) to get signals. I've also had luck with just putting on a large alligator clamp directly onto a spark wire to get the signals.
Someday I would like to build a safer circuit. Haven't had the time.
Ok… so wow!!! This is awesome information! Thanks for this! So please allow me to ask a question… so when testing this ignition signal… do you need 1.) a ground for your scope? And 2.) an attenuator attached? I appreciate your insight, thank you
This is an old thread, many of the participants are no longer active. Andy passed last year. To answer your question, the scope does not need to be grounded but I ground my ignition probe so that if any spark should jump to the probe, the scope will be less likely to take the hit. Also, since this is not a direct measurement no attenuator is needed
Noah, thank you for your response on his behalf. And how saddened I am to hear of his passing. It’s guys like him I learn from the most. I did notice the thread was of age however I couldn’t help but hope that someone would read it. You all seem to stay up on the website. This test would be good for isolation of a bad coil when it’s a cop system?
Nice to see this thread getting bumped! Tons of good information in here.
I started using Honda distributor CMP/TDC sensors as ignition pickups a few years ago. Not my idea, got it from Ray Yergeau at iATN/Diag.net. There's a few posts about making them around here.
Used to be, I had to buy used Honda distributors off eBay and gut them for the sensors. Now, they sell the whole distributor harness (sensors included) on Amazon!
Combine those with some two-wire cable and your connection of choice (banana/BNC), and you've got three ignition probes. Making them this way means you can set the length to whatever you want.
Tyler… I recently had some questions regarding my truck and I bought my launch scan tool,.. which is amazing. The x431 pad 7 elite and would be AWESOME AND PERFECTLY USEFUL if I lived in Europe lol of course I live in Indiana. However the scope is decent. But I’m also new to the digital scopes and I simply just haven’t used them. Now I own a shop and it’s NECESSARY! If you want to be 100% about a diagnosis I must be confident in what I’m selling my customers to fix the issue. So I’m turning to my fellow techs for some assistance.,. Am I not slowing my time line down far enough? It keeps telling me I’m at my limit… channel two the blue is cylinder number 1. Channel 1 yellow is my pip wire. Maybe I’m completely wrong I. All this, this is on my 1995 ford f150. I appreciate it thank you!
I definitely meant to attach photos to my post I apologize: so I think it’s like anything else here. Trial and error. But this o2-2 oscilloscope cost me 700… and then the scan tool was 3300 and it’s great but not on domestic vehicles. But to the point… - I’m going to post the picture of what my post above describes- wave form of my 1995 ford f150 5.8 channel 1 yellow- pip wire and the blue is number 1 cylinder. I want to establish that I’m using my tool correctly so I can use this to help my customers with their issues and of course save myself time and frustration. Thanks in advance. Please let me know if I’m testing the wrong circuit or if I’m using this incorrectly… and this secondary pickup seems like it has an attentunator built in so I didn’t use an extra one at the scope. Correct? And I can go straight to the wire or do I need an extension of some kind?
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