Video: Pico Diagnostics - Relative Compression Test with Pressure Transducer
Fellow founding member Matt Fanslow walks us through performing a relative, cranking compression test with the Pico Diagnostics Software application. In this video, we are using the WPS500X pressure sensor and the 4425 Picoscope interface.
Matt recently joined us to record several videos covering Picoscope which we'll be releasing on DN very soon.
The next video in this series can be found here:
Not only it is an excellent demonstration, it also shows how much the presence of WPS500X transducer affects the relative compression waveform for a gasoline engine. And the answer seems to be: with the right setup, not much! I was unsure about that when I was analysing '05 Mazda waveform from Justin Miller (see below), but now I know.
Very informative video, Thanks Matt and Scott. Matt, Have you ever followed up with an actual compression test to see how accurate ? This would be a GREAT time saver.
One vehicles with starting systems that are in good condition the results are very close, if not dead on.
The WPS500X used with the Pico Technology compression hoses add very little volume to the combustion chamber/cylinder and thus reduce the effects on the compression results.
Excellent overview and video presentation. Matt, I know you are doing a class at Vision (2019) but I do not recall the specific class name?
Thank you, Jorge. I'm co-presenting with Scot Manna. The class is: Advanced Lab Scope Diagnostics (Live Car) all day Friday at Vision (visionkc.com)
One of the MAIN classes that I wanted to attend, Matt. It doesn't get much better then you and Scott together ( Except one year when I attended a Lab Scope class with you and the AWESOME Harvey Chan ). I'll be filling in for that … guy on Friday, Everyone else has filled in for him for the last 15 months, now it is my turn. Anyone that chose to attend this class with Scott and you will be
Awesome video, Scott and Matt! look forward to the rest of the series!
Fantastic! Wish I could attend this year, but can not. Hopefully there will be a recording of that (and ALL) the classes available online....
This test is EXCELLENT. Not only do you utilize the efficiency of a "basic" relative compression test, but you step it up to the next level by correlating the amperage (or voltage) of the relative compression test to actual and accurate pressure readings ACROSS THE ENTIRE ENGINE simultaneously.
You guys made an awesome video, professional quality! It takes a lot of time to make a video like this, and even more to master these skills. I truly hope everyone appreciates the effort you guys put into this, you are the best in the industry, I cannot wait for more! As an educator, I can promise this will be used for years to come. I will be sure to mention this series during my Vision class
Thanks Matt, I appreciate your comments and continued support.
Thank you! I didn't realize that we could add a pressure transducer to the relative compression test within the Pico Diagnostic Software. Very cool!
We've posted the next video in this series here:
Mine wont work with latest software 6.13.14 just hangs when selecting pressure tab. Older software worked fine.
Hi Dustin, What version of the Pico Diagnostics Software are you running? The video shows that we were running 22.214.171.12424
Hello, Dustin. If you are using the latest version of Pico Diagnostics, that was downloaded with your 6.13.14 PicoScope Automotive, there is a known software bug that "greys out" the ability to use a Pressure Sensor. The "fix" is to uninstall your version and install an older version of PicoScope Automotive. I think I'm using 6.12.7.