Waveform Analysis for GM Vortec Atlas In-Line and LS V8 Engines


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Oct 22, 2015
Tampa Bay Area
If you've decided to use any of the Automotive Diagnostic Oscilloscopes such as the Hardware available from Autel, Snap-On Verus, PICO or Hantek, having a ready Base Line of Known Good (and Proven BAD) Waveforms charted to some degree could be very helpful in figuring out the Unique Device Settings and What to Look For... at a glance.

I've chosen the format shown below with Multimedia in mind to provide Quick Thumb Nail Sketches of the Modules and Components being Analyzed, Time Base & Voltage Settings and the links to the Video Instructors as they explain How To Use the Oscilloscope Equipment for each unique problem...and provide the Waveform Clues to solve each one. In time, I'll have many more examples such as these to add to this list after first culling the In-Depth Information, the Screen Images and the Source Media for each Waveform situation:

Waveform Autopsy for Coil On Plugs for the GM Atlas Vortec 4200 Engines:

Component Viewed: Coil On Plugs
Type of Waveform: KNOWN GOOD
Probed Choice: Snap-On 20 Amp Clamp (Hantek CC-65)
Oscilloscope Choice: Snap-On Verus Sub-App
Time Base: 20 Milliseconds
DC Voltage Range: 1 Volt Increments to 15 Volts
Amperage Range: 0-20 Amps
Trigger: Around 1.5 Volts (Notice the Asterisk* Position & smooth, even Ramp Climb)


Source: Paul “Scanner’ Danner YouTube Screen Print:

Waveform Autopsy for Failed EFI on Cylinder #6 on a GM 5.3L Vortec V8 Engines:

Component Viewed: #6 EFI on an LS Motor
Type of Waveform: SCOPED AS BAD (Fuel Injector SHORTED)
Probed Choice: Snap-On 20 Amp Clamp & Back Probed EFI Signal Wire
Oscilloscope Choice: Snap-On Verus
Time Base: 20 Milliseconds
Amperage Range: 0-10 Amps
DC Voltage Range: 0-100 Volts
Trigger: Not Set for Three Parameters (Signal Wire, Voltage, Amperage)


Source: Eric “O” from SMA (South Main Auto) YouTube Video Screen Print:

How to Use a PICO WS-500 Pressure Transducer to Analyze In Cylinder Compression on a Running Engine:

Training Webinar (1.5 Hours) covering In-Cylinder Compression Transducer Wave Form Analysis:

Written Reference Material:

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