How to perform a Relative Compression Test!
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- čas přidán 13. 02. 2024
- In this video I perform a relative compression test with an oscilloscope and an amp clamp. #mobilemechanic #topdon #oscilloscope #compression
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Once past the learning curve the oscilloscope is a useful tool for diagnostics. On a lot of cars today you can't access certain banks without removing the intake manifold. This makes using the compression gauge a time consuming operation. Looking forward to future videos on the oscilloscope. Has that oscilloscope book been a benefit in explaining it's use?
If you are referring to the Waveform analysis book I mentioned in a previous video then yes. That book taught me what good waveforms look like and why. Now if I just get some reps in with setting up the equipment and settings on the scope ill be good to go
Interesting.....For an accurate specific cylinder "Low compression" Only detection test, You should Keep the Removed sparkplug Wire connected to the Sparkplug with the Removed sparkplug Thread/Shell Connected to engine Head/Block ground.....This Keeps the Ignition system electricity Undisturbed & the Removed sparkplug Gap Firing in actuat Low compression (15 psi) Ambient atmosphere Psi Environment.....Leaving the Removed sparkplug wire Disconnected & Not arc/sparking artificially Disrupts the Ignition system that Dosen't happen with a true only Low Compression cylinder problem......Maybe you could Retest & check.....Thx for video...
I considered the spark plug wire being disconnected may not be great on the ignition system but I wasn't really sure what to do with it and since I was only cranking it over for one test I figured it wouldn't hurt too much.
Have you tried using the crank sensor signal for relative compression test, using the same logic the computer uses for misfire detection?
Thank you in advance for your answer.
I personally have not but I've seen other videos of it being done. I am still relatively new to using scopes and shortly after I got my scope I got busy with lots of non scope related work but I still plan to do more videos on scope tests and my learning process in the future. Stay tuned.
@@Andys_Auto Thank you for the reply.
An idea for a video, scope a coil primary (use high resistance probe to protect scope) with injector disconnected with a rev watch end of burn line climb due to no fuel molecules conducting in plug gap.