How to perform a Relative Compression Test!

Рет қаралды 636

5 ай бұрын

In this video I perform a relative compression test with an oscilloscope and an amp clamp. #mobilemechanic #topdon #oscilloscope #compression
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Пікірлер: 7

@mlieser1230 5 ай бұрын

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?

@Andys_Auto 5 ай бұрын

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

@tomstrum6259 5 ай бұрын

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...

@Andys_Auto 5 ай бұрын

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.

@rodvan-zeller6360 3 ай бұрын

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.

@Andys_Auto 3 ай бұрын

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.

@rodvan-zeller6360 3 ай бұрын

@@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.